After installing rEFIt on 3 new MBPs using the installer then booting 10.7.2 it will persistently crash when it runs fsck on boot, powercycling will then work until the next time you boot os x.
On the second boots when it does boot fsck says "Removed 0 orphans / unlinked files and 9 directories"
Sorry just noticed the same issue was reported on thread #3420521