The mili looks very nice! No date though on when they are shipping.
I have it on good authority that mophie has some very cool tngs coming very soon. I have always bought from them and they have great products very durable, last a long time, my juicepak from my first 3g is still alive and kicking as are my 3 air's. They have great customer service if you ever need it so i might just wait to see what they have cooking before I put any money down anywhere else.
Also if you have any old battery paks from your other iPhones just get a female to male iPhone extenstion cord for a couple of bucks and use that till the new ones are released! Works great, not attached but it's a good back up just in case!
Cheers!