Nexus 1 - features I've wanted for *years*
The Nokia 6630 was the first phone I had that could do real networking - it had an HTML browser (not just a WAP one) and Python-for-S60 could talk to phone APIs and the network. Still, T9 wasn't great for entering URLs, and while it was cool that I could get real web pages, it wasn't really a good surfing platform. What I wanted at the time (and made various attempts to implement) was to surf on my laptop, find something I wanted to have on the phone for later (google maps link, most commonly, though "something to read later" was also useful.) On my G1, I actually achieved a crude version of this - from the browser, select the URL, then run a helper that took the cut buffer and made a QR-code out of it, then run the zxing (Zebra Crossing) barcode scanner on the G1 to read it off the laptop screen and open it in the browser (Goggles seems to work for that too but Zebra Crossing is more direct.) Still a couple of steps; I thought about just pushing links to del.icio.us with a "phone" tag and then having the phone look at those, but that didn't really get me a proper queue.
Finally, running 2.2 on a Nexus 1, there's "Chrome To Phone" - a Chrome extension that lets me just click once, and almost immediately my phone chimes and opens the web page, without me even touching it! That's the workflow I was looking for - although the current Android web browser is actually pretty good for surfing anyway.
Another bit I'd wanted was to be able to use a decent keyboard to blog from the phone. The Nokia Wireless Keyboard did work with the 6630, but it wasn't a particularly nice keyboard (from the perspective of someone who prefers the Type M) and the spacing was a bit small... and the 6630 blogging clients weren't really there (best choice was to aim Nokia Lifelog at livejournal, which I did for a while.) On the Nexus 1, I'm actually posting this using Blogaway and the Apple Bluetooth Keyboard (whcih isn't a Type M but has good spacing, a lot more travel than it looks like it has, and when it comes down to it, I can type very fast and comfortably on it which is what really counts.) So perhaps I don't need USB host support to talk to real keyboards after all :-)
The final bit that I'm looking for in my mobile communicating toolset is to go from any of my cameras to flickr, with captioning. So far, FlickrStackr on the iPad (with the same Apple Bluetooth Keyboard, and the Camera Connection Kit) is the option I've used to upload a dozen or so pictures from the field - they bypass my normal workflow, but for highlights or timely shots it works really well. It's also the first thing that's made the iPhone look tempting :-) So I'm still on the lookout for ways to go from camera (or at least SDHC card) to Nexus 1, and thence to Flickr. But I'm quite pleased that the other bits all came together over the years.