I think there are a few things with this dilema...
First of all, I don't think we drafted Martin to eventually replace Long. I think the thought process is play him on the right side, however, he is versatile to play the left side if needed be, meaning should Jake Long have to miss games due to injury. Now, that's not to say he wouldn't replace him permanentley. I mean if Long can't get healthy and misses a significant amount of time this coming year (which is a contract year), then I could see Martin replacing Long permanentley only if Long is not willing to lower his asking price or to a reasonable asking price.
Secondly, I think the other problem here is just that, Jake Long's asking price. I'm sure he wants to get paid and he certainly deserves to get paid up until now, but I think our FO is going to wait and see how he pans out this year. However, If I recall correctly, I remember reading an article a few months back indicating that Jake Long didn't want to re-sign with us and wanted to test out the free agent market, whether its true or not, i don't know. But what I do know is that winning changes everything, and if we can get this team turned around and going in the right direction and Jake Long sees that, he may not want to leave and may eventually lower the asking price.