Video is less a file-size/download issue as it was a few years back. Anything you do in AE can be uploaded to youTube or embedded on your own site with any number of programs these days. One particularly good one comes with Quicktime Pro. Just choose File > Export for Web and it automatically generates all the HTML and reference files for you.
You are right. The internet connection is growing fast (my internet provider have just upgraded my connection from 2/512 to 10/1 to same price and I think I started at 256/128 at same price for 3½ years ago). But how do I make sure that people with slower connections won't get the "anticlimax experience"? Many times I have watched non-SWF videoes and after, say, 20% it stopped because I used up my buffer. Compared to the SWF's preloader system, this can be annoying. How can I avoid this problem?