There is no need to jailbreak the 4G for battery percentage. There's plenty of free battery apps that tells you percentage, and also can break the percentage down for apps/ games/ wi-fi/ music ect...I use Battery Magic and it works fine. Simple!
I'm pretty sure that i saw it in one of the first video-reviews on YT or 've read in in one of those first rviews and some guy mentioned, that battery% is now available thru settings on the new ipt. but can't confirm, since my ipt didn't even ship yet.
Would love for someone to point out where it is found. On the IP4 it's under General/Usage, but IPT4 doesn't have a usage tab obviously.