There are two items of good news in the Wisconsin Recall Bummer. First, Democrats won back control of the state senate, with former Sen. John Lehman (D-Racine) defeating incumbent Van Wanggaard in a squeaker. As Lee Bergquist, reports in the Milwaukee Journal Sentinel,

Results posted early Wednesday showed Lehman with 36,255 votes to 35,476 for Wanggaard with 100% of precincts reporting. The margin of 779 could bring a recount.
…If Lehman’s win holds, Democrats assume a 17-16 majority, at least until next November’s elections. It’s unknown whether the Senate will convene in a special session before then…In November, 16 of the 33 Senate seats are up for election.
Wanggaard’s district – closely matched between Republicans and Democrats – covers much of Racine County. It’s been one of the most volatile in recent Wisconsin history, flipping back and forth five times between the two parties in the last 22 years.

Even if Lehman’s win sticks, Dems won’t be able to move any legislation past the state senate. But they should be able to check Walker and the Republicans to some extent.
The other piece of good news is that exit polls indicate that President Obama had a 9-point lead over Gov. Romney in the Wisconsin exit polls. However, as Chris Cillizza noted at The Fix;

…Exit polls show Walker winning 17 percent of Obama supporters — much higher than Democrat Tom Barrett’s 6 percent of Mitt Romney supporters. Overall, the electorate that turned out today is backing Obama by a significant margin: 52 percent to 43 percent.
Now, all of this comes with a giant caveat; the exit polls initially were pretty far off, showing a close race between Walker and Barrett. Thus, Republicans are casting doubt that they mean much of anything at all.

As for the painful lessons for Dems, you will find plenty of opinions across the blogosphere and MSM. Boiled down, one lesson is that recall elections are generally a tough sell. As Scott Clement, Peyton M. Craighill and Jon Cohen report in in another post at The Fix,

…About three in 10 said recall elections are appropriate for any reason, according to preliminary exit poll results. But the answer depends heavily on whether your party’s candidate is being dragged to the ballot box before their term is up. Republicans said by a near unanimous margin that recall elections are never appropriate or only appropriate in the case of official misconduct. But slight majority of Democratic voters said recall elections are appropriate “for any reason.”

Another lesson is that organized labor needs to do a better job of educating the public about their contributions and role in protecting the middle class. Too many voters seem to have bought into negative stereotypes about “big labor,” as a result of labor-bashing propaganda, which now seems to be an even bigger element of the GOP agenda. Unions need more assertive mass media/public education outreach.
A third painful lesson is that even great GOTV doesn’t necessarily trump money. Barrett was outspent 7-1, which can’t be unrelated to his defeat. An interesting question here is whether Walker also had energetic street-level GOTV or just an ad war edge.
If lessons are learned and strategy is tweaked accordingly, Democrats should be able to hone their edge for future campaigns.