I think we also need to consider that Lubanski is 1 1/2 years younger than Ellsbury, so they shouldn't be compared as if they were equals. If Lubanski went to college he would have just been drafted this past June, and I would guess that most people would be very pleased with his performance in AA this year if it were his first minor league experience.
When you examine the fact that Lubanski is 1 1/2 years younger and still has an OPS that is quite a bit higher than Ellsbury, i'm not sure why anyone would automatically make the leap that Ellsbury is the better prospect. Lubanski hits for more power, Ellsbury get on base at a higher rate; Ellsbury has better command of the strike zone, but Lubanski improved quite a bit this year in that regard; Ellsbury is probably a better SB threat at this point, but Lubanski has some wheels as well (11 triples this year).
It seems like Lubanski has been a forgotten prospect ever since he missed most of 04, but he had a huge year last year and has improved his ratios this year even with the leap to AA.