Here's a reply from Jeff Schewe (one of Martin's colleagues) on Martin's comments. This is pretty reassuring for most people, but there are some known (to a few, at least) incompatibilities.
...Depending on the way in which old "Sets" were made via linking and the changes to the behavior of "Groups" vs "Sets", actions that produce layer sets via linking in Photoshop CS may need to be rewitten in some cases for CS2. For PhotoKit, all of our "old CS" style linking behaves well under CS2's Groups. For Martin's PhotoKit Color, the manner in which he created the Sets was a bit different and thus produces different results under CS2 than CS. |
As for the type actions, that was again the way in which he resolved the Sets, it has nothing to do with the text layers per se.
I will say there was a period there where old actions were pretty much completely broken. But several of the Photoshop engineers and Q&E people worked VERY hard to enable as MUCH legacy action support while changing the layer Group behaviors. They weren't 100% successful, but it's gotta be in the high 90's.
Simple actions without complicated layer set construction should not be effected at all.
As for the other things that WON'T work, about all I can say is try it in CS2. The changes aren't hard, however it should be noted that to fix it if it's broken in CS2 will basically break it for any previous versions. The vast majority of people will never know though. . ."
It's curious that Adobe wasn't up front about this issue. Their stance was most likely, "Let's not say (publish) anything (stirring up unwarranted concern) and we'll deal with the few problems one at a time as they come up."
Anyway, now we know.