There's no question about which version of Android it's running and I assume the name is just being used to refer to newly manufactured Streaks that will ship with Froyo preinstalled. It's possible that there could be other changes too (e.g., parts from a different manufacturer), but that remains to be seen and isn't worth mulling over just yet.
What's interesting about the "Streak Froyo," according to someone who attended a private Dell presentation about upcoming products (laptops, phones, and tablets), is that it is said to be coming in "more colors" this month.
Whether it's just the red one that other countries have had for months, the white one that Best Buy is supposedly getting this month, or some of the other colors that have only been seen on paper, it sounds like new Streak buyers will have it much better than we did.
Froyo and a color other than black right out of the box? That sounds like something AT&T might want to start selling in its stores to me.
Thanks, anonymous tipster!