I've read comics online before and then gone out and bought the issue. You're right, there's nothing quite like the feel of a comic in your hand and turning those pages as you read them. Plus, you can't read a comic in the bath when it's online!
But, for some comics you need to be reading 2 or 3 other titles at the same time just to keep up on what's happening. Having the comics online will allow those people who can't afford to buy them all to keep up to date.
Personally I think this will benefit Marvel by giving even more exposure and branding to their many titles. I reckon comic readers will ALWAYS buy comics, I don't think the online format will ever be a full substitute for real comics.
