I just finished the update to baselayout 2 for ethernia.net, using this pretty handy gentoo guide:
I have to admit i was pretty scared about the idea that i just might make the system completely unbootable, but everything seems to be working just fine for now. But apparently, as long as you follow carefully the documentation, you should be fine.
Just a little thing, if you have to do this migration too and, like me, use a non US keyboard and happen to have encrypted disks that need password entry during the boot sequence, there used to be a glitch on baselayout 1, where the system would be in qwerty even with your keymap set to a different keymap in /etc/conf.d/keymaps . Just keep in mind that this time your system will boot with the keymap you have set, so you might need to enter your passwords with the normal keymap this time.
I still have a lot of PHP related work to do before I can resume my usual SL activities.