Kay Bailey Hutchison is vacating her Senate seat and running for Governor in Texas. This is good news, as she would've been really tough to beat. She'll be presenting a primary challenge to Gov. Rick Perry.
The top Democrats running for Senate include Bill White, the Mayor of Houston, who intrigues me because of his amazing support in the city. He's won reelection with over 80% of the vote in the past two elections, and faced only token opposition. It looks like no major Republicans even stepped up to challenge him -- last time he was against a socialist and a guy who changed his name to 'Outlaw Josey Wales." I don't know how he's perceived in the GOP-leaning exurbs, though, and it appears that the city itself has 2.2 million people while the metro area has 5.7 million. So it's possible that we shouldn't read too much into his big numbers. This may be a case where Beaudrot's law kicks in -- don't run the big city mayor for statewide office unless he has a good relationship with suburban/rural voters.
The other person who's raising big money is former Texas comptroller (1991-1998) John Sharp. He has the virtue of having been elected statewide, but has also lost statewide when running for lieutenant governor in 1998 and 2002.
Both guys have relatively low name recognition but decent favorability numbers. They actually win against some lower-tier Republican candidates, but lose against more likely opponents like David Dewhurst, who beat Sharp in 2002. According to this, Dewhurst seems to want to join the Republican Governor traffic jam in 2010. That's from earlier, so maybe he didn't know what Hutchison was doing at the time. (Why don't Republicans want to be in the Senate? Even if you're in the minority, it can't be that bad a job. Do they think the Bush path to the presidency will work again?)