Democrats took back the House, and in a big way. At present, Dems can boast a net gain of 29 seats, if Joe Courtney can hold on in CT-2. There are other races that have yet to be called, but all of them are tilting ever so slightly away from Democrats.
Democrats, in all likelihood, also took back the Senate. Rick Santorum is gone. George "macaca" Allen is gone. So are others. As Brad DeLong Points out, the 50 Democratic/Independent Senators represent 10 million more voters than the 50 Republican Senators.
Democrats made significant gains at the State Legislature level, gaining about 275 seats out of 6000 or so that were up for election. Dems now represent 53% of all elected office holders at the state level, up from a 50-50 split.
Gay-bashing is not universally popular. Arizona Proposition 107, to ban same-sex marriage again, failed. In some states (Colorado, Virginia, Wisconsin, and South Dakota), same-sex marriage bans passed, but with less than 60% of the vote, a moral victory of sorts.
Nothing is the matter with South Dakota, either. Referendum 6, to uphold the state's ban-all-abortions law, failed.
So-called "Taxpayer Bill of Rights" initiatives to starve state & local governments also failed in three states, further proof that America recognizes there's a positive role for government and we shouldn't hamstring it.
Locally, I-920 and I-933 both failed, allowing state government to pass responsible environmental protection laws and keep a bit of money in the state's education fund. I-937 passed, but amazingly 47.5% of the people of Washington were willing to vote against puppies. Democrats also made substantial gains in the State Senate and State House, though I can't find a good set of results anywhere.
The Bad
Gay-bashing, while not as popular as it was in 2004, is still popular. Initiatives to make gay marriage extra super double plus illegal passed in eight states.
Seriously, that's about it. Republicans made gains in the Oklahoma House, and, it appears, took control of the Montana House (which was already balanced on knife's edge), and pushed the Montana Senate to a tie. But local candidates can be considered on their own merits; it's only at the national level that a vote for the Republican party is unconscionable..
The Ugly
In Minnesota, Mike Hatch's (D) boneheaded comment (or non-comment, depending on whom you believe), may have cost him the election. Note to self: avoid blatantly chauvinist words when describing the right wing noise machine.
Harold Ford Jr. couldn't quite pull out a win in Tennessee. It was always a long shot, and the polls after the airplane and church ads were clearly too optimistic. In the end, Ford made headway in some areas of Central & West Tennessee that were surprising, but he couldn't quite convince enough people in East Tennessee to vote for him. Obviously, it would have been a sign of incredible progress if Ford had managed to become the First African-American Southern Senator Since Reconstruction.
Democrats seem to have left a lot of squeaker races on the table. OH-2, OH-15, NM-1, NC-8, WY-AL, FL-13, and PA-6 were all razor thin races. Several others were nearly as close: NY-24, NY-25, and NY-29 to name three. Gaining 30 seats is nice; gaining 40 seats would have been incredible. On the other hand, Dems certainly ended up ahead in their share of squeakers as well.