I'm surprised they are both around in the 4th, can't really go wrong with either but I'd probably take Jeter. Batting 2nd will probably raise his value since his RBI will go up more than his R's go down. Rollins is so streaky he scares me, if he doesn't have his annual hot streak in the 2nd half he won't come close to Jeter's value.
I think Rollins is going to put together another great year. I don't think it's a reach to expect his batting average to be a minimum of .300, for his RBI total to go up just a little bit, and for Howard to drive him in a lot. That being said, Jeter's power numbers are much better and the Yanks are going to score a rediculous amount of runs this year. Being near the top of the order should be very beneficial for his run, at bat, and hit total. I'd give Jeter the slight edge over Rollins, and I love J-Roll.
I'd go with Rollins, but you're fine picking either.
Rollins and Jeter are equal in runs and AVG (I think Rollins AVG will increase this year and be a .300 hitter.) Jeter will hit about 5-6 more HRs, and drive in about 20 more RBIs, which is significant. However, Rollins will steal 20-30 more bases than Jeter will, and that's where Rollins takes the lead for me.
If you plan on drafting several 15-20 steal guys, I'd pick Jeter because of the higher RBI totals. For most teams though, take Rollins.
...Boston papers now and then suffer a sharp flurry of arithmetic on this score; indeed, for Williams to have distributed all his hits so they did nobody else any good would constitute a feat of placement unparalleled in the annals of selfishness. -Updike