Okay... That's good to know. Sorry for the thread-jack. One last question... Can I assume that my current Ultimate world can be played with the beta 1.5 pack with some acceptable side-effects?
I'm not a MODDER, but I play a LOT so I'm trying to be more involved, in a positive way, with the FTB community. Thanks for the response.
FTB stated a few times recently that the 1.5.2 pack will not be compatible with the 'old' Ultimate for Minecraft 1.4.7 pack. And that the soon to be released and yet unnamed 1.5.2 pack will most likely not be compatible with any future Minecraft 1.6 pack.
The only way to keep your world will be to continue playing with the old pack (which will continue to be available to you).
There 'might' be a world converter released at some point from what I've read, but it is 1) far from a guaranteed proposition and 2) far from a perfect tool (buggy) and 3) it will only help with ID/config changes and wont help with mods that have been removed (because no 1.5.2 version exists) or changed too drastically (most notably redpower, Xycraft). Your house was in a volcano? too bad, its now empty air. That nice marble house? Yea, that would be gone too. Any fancy wiring, timer state cell or micro blocks? Poof. All those great Xychorium bricks that stop mobs from spawning in addition to be colorful? Nope.