Your overall premise is right, but I think you're way off on the timing. Sure, today, you can stream 720P from Netflix and the likes, but not all 720P is created equal. Just because you have 720 lines of resolution doesn't mean it's going to look even remotely good. I watched a movie on Netflix last weekend (supposedly in "HD"), and it looked like shit compared to a DVD. The problem would only be exacerbated with a 1080P signal, because I can guarantee you that they wouldn't devote an additional and proportional amount of bandwidth to account for the increase in resolution (i.e., even higher compression ratios and loss of quality). Of course, there's also the problem on the ISP end as well: When your ISP is also providing the majority of your TV content, they're going to do everything possible to discourage you from streaming from any source other than themselves (i.e., bandwidth caps), regardless of whatever technical limitations exist (and for the vast majority of America, there are still technical problems in place on download speeds, at least as far as "true HD" streaming is concerned).
Now, you could argue that a lot of people just don't care that much, and you'd probably be right. But BluRay will continue for at least a few years for what I think is a relatively large niche of people who *do* care about the quality. On our 63" 1080P plasma, the difference between BluRay and streaming or DVD is so huge that there's no way you'd want to watch anything but BluRay, given the option. And while I'm the resident videophile, even a normal person can notice the difference...