Not really as much as you might think. With a 10MP camera, it will easier to make large prints or to crop...but even a good 6MP DSLR can result in great looking prints 8x10 and larger.
That is what I was thinking. I ran into that with my little point and shoot canon. I took a REALLY nice shot of a sunset over the ocean and the camera was only like 3-4ish MP. I emailed it to the guy who I use to print all my stuff and he told me it would be hideous if I blew it up.
I want to be able to have my pictures printed for my office or to frame and put around the house. I am really leaning towards the Nikon kit right now mostly because it looks like I could get out the door for $600 and have a good little starter kit. I might also get a wide angle lens for some good scenic ocean shots, what exactly does the wide angle lens do?