First off, read the Rivers tutorial which is a sticky in the tutorials, your rivers need work, they split and do some unnatural things. Seem to see a couple spots where a river disappears also, or that could be forest covering the river... not sure. Rivers also seem to be going over terrain that is still visible in the river, also.
Whereas many maps have coasts that appear too smooth, yours almost goes the other way with jaggedness that still has a smoothness that has the feel of randomized computer handiwork. This isn't necessarily a bad thing, just goes against the tastes of my eyeballs.
Your mountains also appear to lack rain shadows.
In general I like the colors and basic shape of the land mass.
Okay, that's it for now, gotta run! LOL.