I think 0.6.0rc1 broke my blk0001.dat, blkindex.dat or something else not located in .bitcoin/ (is there something else?)
When I get home I will also delete these files. (I have a 170190+ blockchain here that I will try first, before downloading the whole thing again)
I thought this too.. but mine did recover after ~5 min after installing rc2.
I gave it another hour, but it didn't recover. I copied the blockchain files from another machine and now it works.