So far, so good.
Used GParted Live CD to resize my XP NTFS partition. http://gparted.sourceforge.net/livecd.php
Installed the beta and chose new install with the unallocated space selected.
Windows 7 killed the GRUB bootloader, but that's easy enough to get back. It boots fine into Win7 or lets me select Win XP
It's lightning quick and seems to be stable.