Very nice so far! 2 things, one IMO is a bit more important(first one), the other not so much:
The rivers look a bit to fat for the most part and uniform in width. I know this is VERY hard to get right with just a mouse, so I totally understand. I bought a tablet mainly for the purpose of drawing rivers with variable widths.
You may want to consider using a noise layer set to overlay just over top of your grass and below rivers, forests, etc and masked with the land mask. This will get you a bit more color variation in your green grass layer with no manual painting and very little over all effort. If you feel like it, you can play with it over your dirt also, but I don't know how if that will look good as I have not tried it myself. Take a look:
http://www.cartographersguild.com/at...3&d=1212462223
between the two big forests for an example and give it a try to see if you like it. I think for "mine" I actually did two different overlays with differnt noise settings to get something l liked.
Joe