I think it's odd. A clear case of cronyism, albiet in its "best" sense (in that Bush chose the best lawyer he was familiar with), but based on her merits...well, she doesn't have a lot, does she? Active in the Texas bar at least, which is probably the best positive I can see about her.
The biggest problem with the nomination that I have is that she has no track record to judge, which means that when it comes down to the Inquisition, she'll be judged exclusively on personal and partisan grounds...which makes me wonder if this isn't meant to instigate some sort of partisan reaction to prompt some sort of "Up yours!" to the Senate Democrats, as I certainly don't see a lot of judicial sense in it.
As for Miers' suitability for a Supreme Court seat...I wish I could judge her on her own merits instead of Bush's lack thereof...but I can't see where she has anything to suggest her, good OR bad. Like I said, odd...why nominate someone that no one can judge?