So many House districts undefined, and so many questions left unanswered.

As the new year begins, just 28 new Congressional maps are in the can, with a few awaiting approval from the Justice Department and several more the subject of lawsuits.

As a result, there’s still a lot of unsettled territory on the redistricting landscape.

Most importantly, which party will pick up more seats following the once-in-a-decade redraw? Republicans were initially believed to have had an advantage thanks to the massive gains they made in state legislatures, which mostly control the pen. But Democrats caught several lucky breaks in the courts that have softened that blow.

Here’s a look at the greatest redistricting unknowns left this cycle.

1. How far will the Supreme Court reach in its decision about the Texas map?

The Supreme Court even surprised Republicans by granting the GOP’s request for a stay on a lower federal court’s prescribed Lone Star State map that favored Democrats. The high court scheduled opening arguments for early January, after which the justices will determine whether a federal three-judge panel overstepped its bounds with its redraw.

There are four new Texas House seats at stake in the case, and each party stands to pick up at least a couple of them depending on how the lines are drawn.

But the Supreme Court could choose to decide so much more in this case. It’s within the court’s authority to bring up other redistricting legal concerns in its ruling — even the constitutionality of Section 5 of the Voting Rights Act.

Top Republicans have long questioned whether that part of the VRA is constitutional. For example, House Republicans’ point man on redistricting, Rep. Lynn Westmoreland (Ga.), voted against VRA reauthorization in 2006 because he believes it’s unfair only some states — such as Texas and Georgia — require Justice Department preclearance under Section 5.

Ironically, if the Supreme Court included VRA commentary in its final decision on Texas, Democrats might stand to benefit more. Section 5 requirements force mapmakers to pack minority voters into single House districts to retain their influence. Mapmakers could spread out the minority populations — who tend to vote for Democrats — to make nearby districts more competitive.

2. How will federal courts interpret the Fair Districts law in Florida?

Florida is one of the maps yet to be finished — and it’s also one of the most important. A boom in the Hispanic population gave the state two new House seats in 2012, plus many more already competitive seats are at stake depending on the new lines.

Florida lawmakers have released several draft maps, some of which put GOP Reps. Allen West and Tom Rooney on unstable re-election turf.

But those maps might be a moot point by this spring. Federal courts could hold the cartography pen in what most political insiders expect to be a drawn-out legal battle.

The Florida maps must adhere to the state’s new Fair Districts law, which forces mapmakers to construct districts that are, well, fair. It’s a new law, so it’s anyone’s guess how the courts will interpret it for the new maps.

Secondly, Florida’s new maps must also pass muster with the Justice Department or the District of Columbia’s District Court. Parts of the Sunshine State are also subject to Section 5 of the Voting Rights Act.

All in all, it’s going to be a long, litigious journey.

3. Will state Senate Republicans cut a deal in New York to save themselves and sacrifice the GOP House Members?

New York is losing two House seats because of population decline, so at least a couple of Members are on the chopping block. New House Members, such as special-election victor Rep. Bob Turner (R), and Congressional veterans, such as Rep. Louise Slaughter (D), are at risk.

But mapmaking control is a mixed bag in the Empire State, where Democrats control the state House and governor’s office but Republicans control the state Senate.

Congressional Republicans are increasingly worried their state Senate colleagues will cut a deal to save their own seats on the legislative map, meanwhile throwing their Congressional colleagues to the wind.

It’s a unique situation — even for redistricting. Albany’s political egos are comparable only to those on Capitol Hill, and it’s hard to imagine state Senate Republicans won’t pursue whatever means necessary to save their own seats first.

4. Who will benefit from the court-drawn maps in Minnesota and New Mexico?

There are few seats still up for grabs in Minnesota and New Mexico, where legislative standstills forced the courts to pick up the mapmaking.

Party operatives are watching the boundaries on at least one seat in New Mexico. Rep. Martin Heinrich’s (D) departure to run for Senate leaves competitive territory open next year, and new lines could swing that district in either direction.

Meanwhile, three or four seats could be competitive in Minnesota depending on the new lines. The courts are expected to release a draft map this month — just in time for the Gopher State’s traditional caucuses next month.

5. How many more retirements will come before the remaining maps are finalized?

It’s been a pretty tame retirement season this cycle. Only nine House Democrats and two House Republicans have announced they won’t be seeking re-election. That’s a low tally, especially for a redistricting cycle.

Many Members contemplate retirement each cycle, but the daunting task of getting to know a brand-new district often puts them over the edge. Rep. Barney Frank (D-Mass.) admitted as much in November when he decided not to run for a 17th term.

In other words, a wave of anticipated retirements might still be on its way.

Specifically, watch out for potential retirement announcements in states without finished maps: Florida, Minnesota, New York and Texas. Once some Members take a gander at the boundaries, they might decide it’s easier to move to the private sector than to move to a new district.

Correction: Jan. 3, 2012

An earlier version of this story incorrectly stated the number of Congressional maps completed and the number of House Republicans who said they would not be seeking re-election. As of today, 28 new Congressional maps are completed and two House Republicans have announced they won’t seek re-election.