I already told you a similar story when I discussed PL/I for z/OS V4.1. And the title of this webcast on DB2 10 is telling you exactly the same message : they both offer more functionalities but at the same time they should consume less resources.
This webcast should give you some good insights on DB2 10 :
There is also a DB2 10 Beta customer telling his story and there's - what should be - a very interesting Q&A session with some of the most famous DB2 names around.
"In this session, you’ll learn how DB2 10 for z/OS delivers:
The Webcast is on Tuesday October 19, 2010, will take about an hour and a half and starts at 5 p.m. CET (Brussels). You can register over here.
You can find more details on Willie Favero's blog. And if you already want to have a better idea of some of the topics that will no doubt be discussed, you can have a look at this z/Journal article : 'Top-10 Features of DB2 10 for z/OS: A Preview'.