Rule updates in PHB 2

As part of the March previews article, Wizards has shown the table of contents in Player's Handbook II. Among other useful information (such as the number of pages, 223, which I didn't know) there is an interesting tidbit: a chapter dedicated to rule updates. These updates focus on two major issues, Reading a Power and Stealth. I wonder if they will have new material, or just be a compilation of published errata, though. This are the sections of the chapter:

APPENDIX: RULE UPDATES	218
Reading a Power	218
The Power Format	218
The Power Description	218
The Marked Condition	218
Movement Effects	219
Keywords	219
Extra Damage	221
New Stealth Rules	222
Bluff	222
Stealth	222
Perception	222
Targeting What You Can’t See	223

It's just 6 pages, and it looks like it will consist on errata-like updates. On the other hand, Stealth rules in PHB were poorly written, to say the least, so this should prove useful.