There's been a lot made of the fact that the iPad doesn't support Flash. But how much of an effect does it have on day-to-day browsing? I snagged screenshots of 20 top websites so you can see for yourself.
There are really only a few sites that are noticeably broken by Safari's lack of Flash. Hulu, obviously, is a big one. MySpace also loses the only thing its still useful for with the death of its music streamers. CollegeHumor hasn't made the transition to HTML5 despite its sister company Vimeo working fine. And IMDB's main page loses the top half of its main page (although their app is pretty great, so that's a workaround). Netflix works OK, mostly, but star ratings are not clickable, and you can't rearrange your queue by dragging and dropping. Gmail's mobile site looks great and like an app, but can get thrown off by formatted, HTML-rich messages that are wider than its message pane.
But overall, most sites look just fine. Many of the big ones, such as NY Times, CNN and ESPN, play videos just fine. And obviously sites like Wikipedia and Craigslist look just great.
A couple of sites send you over to their mobile version for some reason, such as Twitter, despite the iPad having a resolution equal to many normal-sized computers.
But the bottom line is this: with the majority of major sites having made adjustments to have video work on the iPad by launch day, within a couple of months the only sites that won't work will be sites that don't want to work on the iPad, such as Hulu.