Perhaps you've recently done an exhaustive search, but I just picked up a new EA backpack (with the Wizzy 110) from Jong at Jive Sound a few weeks ago. Bass Central also had both in stock at that time as well.
I had been under the impression that you couldn't find these anywhere currently, but I was pleasantly surprised to find them...
I have found very little use for my backpack although perhaps I will change my mine when the weather is bad. When I don't have to expose the speaker to rain or snow, I'd much prefer to just carry it. I carry the Micro 300 either in the bass bag pocket or in another bag with a shoulder strap. I find the backpack takes too much mucking around for setup and teardown and carrying on your back with either one or two straps is not all that comfortable.
