Well, this is just a matter of time. It's all the card manufacturers too, it has nothing to do with the devices. We're already seeing 2GB microSD so I'm pretty sure in 6 months or so we'll see 4GB versions.
The T-Mo SDA has almost all of that. It's MicroSD with WiFi-B, No A2DP but there are some hacks out there to do it.
Anyway, you're specs aren't all that far out. I'm sure we'll be seeing something in the not too distant future that would have all these things rolled into it. I'm very happy with the Samsung i320. If they added Quadband, and improved the battery then I would be in love.

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"I have no special talents, I am only passionately curious" - Albert Einstein