Very nice! It is a pretty cool idea. I like the way you did your texture and the mountains, I really like them.

How are you planning to tackle the line of your coasts? It doesn't blend too well at the moment. (Just FYI, I'm not talking about their natural contours, that actually came out good as well.)
I was wondering if you are going to select your land mass, grow the selection by a few pixels and throw in a dark color under the land mass and blurring it? Or what are you looking at?

(By the way, is this your second map ever? Or just second map in your world. Either way, job well done so far.)