I had no idea you could root the phone when I bought the Hero. Got it in perfect shape like new on Craigslist for $100 because the guy got the Evo so that he had the wireless router, and he said even if I got it to work on the Hero by hacking it Sprint would be sending me enormous bills. And it was SO easy, jailbreaking the iPod Touch was a lot more involved.
Can make and receive unlimited calls for free using Google Voice and SIPgate, have the wireless router, can install to SD card, etc. I would NOT buy a phone that can't be rooted. It's not a how-cool it is thing, it's a how unbelievably useful the phone becomes thing.
Having said that, most Android phones will sooner or later be rooted
And I honestly think I have as good a phone as the Evo. I figured the Evo will be $100 in a year on Craigslist and I just wanted something Android to get me started (have had it for a week). This fit the bill.
Oh and like someone said above.... I'm running Froyo 2.2 on a phone that's probably never going to officially get it
I have a feeling the Hero is going to be supported in the rooting community for a long time and this allows me to take advantage of the new apps that come out that use the latest OS.