BTW, I bought my Charge at Best Buy. Their web site still shows no sign of it, and it wasn't on display at my local store as of a few days ago, but my store at least has had the units in a locked case been selling them to anyone who asks for at least a week.
To clarify: the Charge has *only* the micro USB port for charging - there is no other power input. Yes, any 2 amp input will work equally well, lower amperage may work but will be slower. Mac USB ports apparently have higher amperage than the standard calls for, PC users can download
http://event.asus.com/mb/2010/ai_charger/ (not just for Asus PC's) to up the amperage of their USB ports. I've been using my iPad charger with the Charge, but it also appear to charge from my generic car charge as well as my Asus-enhanced PC USB ports.
Pairing: the Charge has no special mode for multiple pairing. You have to unpair from one device ("forget" from the phone, or by putting the Charge into pairing mode) in order to pair it with another. So if pairing to multiple devices is important, this is not the device for you - it can't do that. Ditto if you require speakerphone capabilities - it can't do that, either. Reading battery level from one's phone was mentioned as important to someone, although I can't really imagine why - but no, it can't do that, either.
What it *can* do is sound better and louder, and last longer, than anything else you'll find for under $200.
Compared to the Logitech UE Mobile Boombox - there is no comparison. The Charge just blows it away, easily verifiable in an in-store comparison (use the JBL Flip if Charge isn't out yet - they are very similar, although the Charge is slightly "fuller" in sound). To its credit, the UE Mobile might be close to as good as the Flip/Charge at lower volume levels, but lower volume levels is pretty much all you can get out of the UE Mobile Boombox. Now, it's bigger brother, the Logitech UE Boombox (no "Mobile" in the name), is another story - it's pretty amazing. But it also a different price range and rather less portable.
Compared to the Bose SoundLink II - based on my in store comparison with the Flip, I'd agree the Bose is better. But not leaps and bounds better - I'd say the Charge is closer in sound to the SoundLink II than it is to the UE Mobile Boombox. And I definitely don't hear the Bose as being enough better to justify the 2X difference in price, or to put up with proprietary charging or lower battery life (the whole reason I waited for the Charge rather than just buying the Flip a month ago).