He has the potential to stick somewhere, but he probably only has a 2 year window before teams will stop giving him a chance. The Mets already have a similar type bat in Flores (could probably hit 20 homeruns but hasn't shown the ability to hit for average) and he's 3 years younger than Olt. Of course Olt is a superior defender but he's also a career .158 hitter.
Don't get me wrong though, I'd love nothing more than to see an infield of Olt, Mazzilli, and Siena all succeeding for the Mets. Just don't think it's in the cards. Of course now that they added a 2B and 3B there's no room at all in the infield so it's moot anyway.
Meanwhile, Mazz is doing alright at AA and will probably at least get a shot at some point in the next year or two due to injury or September call ups. Siena continues to hit for average but has shown no power (40 hits in 128 at bats but only 3 XBH - all doubles). His strikeout rate is pretty low so hopefully he can figure things out a bit and find a way to start putting line drives in the gaps.