This is a big deal: HTC won’t lock its Android bootloaders, any more. Quotes from the post:

• HTC has thrown down the gauntlet with carriers. [...] Carriers use [...] exclusives as key opportunities to push their brand and establish and protect revenue streams, and a big part of that involves locking you into a branded ROM. In light of this announcement, HTC can no longer promise its carrier partners that it’ll play ball on that
• They’re taking on some additional warranty liability (and bringing carriers along for the ride, whether they like it or not).
• It’s a tacit admission that Sense isn’t for everyone.

What does this mean for users? If you are not a technical user, not much. If you are, though, it is a big deal: You’ll be able to easily root all HTC devices and, among other things, to get a pure Android experience. The announcement on Facebook has already lead to many comments.

From http://www.2ality.com/2011/05/htc-unlocks-bootloaders.html