I’m voting Obama, because I think McCain’s policies in general (with a few exceptions, such as his support for environmental policies and sound science) echo those of George Bush (though, of course, I think McCain would be far more competent in execution), and I think those policies in general are not good for the nation right now.
I’m also significantly concerned (as one other person above mentioned) that appointment of just one more justice who is very conservative could overturn a great many protections in the US for workers, minorities, and others. Frankly, I much prefer the courts to be on the “little guys” side rather than that of the corporations (who, I think, have enough advantages as is), so while I like a fairly balanced SOTC, I’d rather it to be tilted just slightly left of center, and as of right now, it is tilted slightly right of center with 4 very conservative justices (Alito, Roberts, Scalia, and Thomas), one justice who leans conservative (Kennedy), one centrist (Souter), and 3 liberals (Ginsberg, Breyer, Stevens), with the most likely upcoming replacements being of the liberal justices.