Ah yes, the elusive wacom - I got myself one after finals last year as a prize for not losing my mind.
Anyways, these, as I said before, are good, but they have even more potentail. Unless you are going for a very vague look (which is a matter of preference), you should try to sharpen up the detail. In the second picture, I was drawn to the heart because it gave me a lot to look at, which I liked a lot. Also, when you are coloring, the best thing to do is to lay out a neutral color instead of white as a background, if you don't already. That white is scary, yo.
Hrm, I think that is all I can contribute. Sorry if it wasn't particularly useful; I'm not sure what you are going for. That said, though, I think that painting these (with acryllics?) would make them very, very cool. I like traditional media a lot.