After seeing mM updated to support this firmware, I updated from Rogero 4.21 v1.09d to E3 4.30 (via XMB)...absolutely no problems installing it or running it. mM 4.08.01 installed and operates perfectly.
In a previous post, i'd mentioned holding off until a 4.30 signer was made...but what flew over my head was the fact that the 3.55 keys were blacklisted; thus the 4.21 resigning tool. Showtime 4 (4.21 signed) works absolutely fine as well.
So (as far as I can tell), there's no reason not to update. If anything happens, i'll post on the forum.
Last edited by r2rX; 10-28-2012 at 04:53 PM.