First off, I'll always view keeper leagues as a "must-win" now rather than later until proven otherwise. The basis of a keeper should always be in position to win now and in the future, with the focus of now. A player with the best combination of youth, upside, some kind of track record, and some room for improvement is ideal but that shouldn't knock down the value of an older player that can be more productive now rather than later. For example, Soriano at #31 is quite low (I'm still thinking he's a keeper in the #10-15 range).
That said, at times, you might want to take chances on upside. Longoria at #15 might sound really bullish heading into next year even in a keeper league but based off his rookie year where his flyball rate is a bit better than expected and his line on just short of a full season, he could likely be a better option within or exceeding 5 years than say, Jimmy Rollins. On top of that, he has room for improvement to build off such ceiling. I don't think an established player like Carlos Lee or Carlos Beltran with little marginal added upside, past their peak season, is as lucrative as Longoria I'd say.
With regards to the list, Sizemore's a little too high (#10-15 sounds fine) whereas M-Cab and Holliday are still bona fide top 10 keepers. Johan Santana and Ichiro are quite high for my liking as well.