The star of this year's set has to be the Platinum Diamond Anniversary cards. This has to be the card set of the year. They are awesome looking in hand and definitely have a 90's insert vibe.
Another great insert set is the Kimball Champions set. It is a (so far) 50 card mini sized set. I think I'm going to attempt to build this one. They have great images on them and the set features a solid list of HOF'ers and current stars. The only bad thing with the 4 I hit was that 2 got caught in the pack sealer and got crimped.
Another new insert set for 2011 is Vintage Reproductions set. Topps is going back and reprinting some of the great old cards from some of the all time great baseball card issues.
Replacing the Topps Million Card giveaway card this year are the Diamond giveaway cards.
Topps Diamond Giveaway site.
I ended up getting 3 of them but will have to wait until the site gets up and running later this month.
I was also lucky enough to get a Don Mattingly jersey in one of the last packs I opened. Nice designed card. I'm not sure I like the dark boarders of it but it could grow on me.
Also remember to save your hobby wrappers for the announced series 1 wrapper redemption program.