I have to say that I'm rather unimpressed by Marvel's new Digital Comics feature.
Representing on screen comic books originally produced for the printed page has a variety of challenges, but they boil down to two:
1) How do you present a page (or a two page spread) as the whole element, while at the same time allowing readers to zoom in close enough to read the words?
2) How do you handle navigation?
Marvel chose to handle problem one by allowing readers to zoom in on individual panels, making the words legible but leaving the pictures pixelated. They handle problem two by offering a large menu of confusing navigational options. It's a rather frustrating experience.
Contrast this with the now-defunct CrossGen Comics far superior Comics on the Web, where users could use the tab key to cause successive word balloons to zoom up to a redable size, and navigation was done with simple keyboard commands. CrossGen also had other features, such as the ability to get rid of the text entirely, or turn off the computer coloring and view the pages in raw inked black-and-white form.
This is Marvel's second try at offering online versions of their comics, and I think that it's actually worse. Hopefully the third time will be the charm...