The first real reviews of Google’s first Android phone, the T-Mobile G1 (otherwise known as the HTC Dream), have begun to emerge, a week in advance of its release in stores.

Walt Mossberg of the Wall Street Journal has a detailed first look. Andrew Garcia of eWeek has a lengthy review. John Brandon of Computerworld has a first look and review round-up. But the reviews thus far have been focused on the core phone functionality, and it’s not clear to what extent the available third-party apps explore the capabilities of Android.

I am personally looking forward to checking out the new phone. I was an early user of the T-Mobile Sidekick (aka the Danger Hiptop), and I loved its rendering of webpages (and its smart proxy that reduced image sizes, did reformatting, and so on), its useful keyboard, its generally easy-to-use functionality, and the fact that it stored all of its data on the network, removing the need to ever back up the device. I was disappointed when the company did not follow through on its promise of broad third-party apps; despite release of an SDK and an app store, you couldn’t use third-party apps without voiding your warranty.

These days I carry a corporate-issued Cingular 8525 (aka HTC Hermes), but despite it being a very powerful Windows Mobile smartphone, I actually use fewer apps than I did on my Sidekick. I use my phone to tether my laptop, for SSH access to my home network, and for basic functionality (calls, SMS, browser), but despite one of the best keyboards of any current smartphone it’s still not good enough to for real note-taking (with serious annoyances like the lack of a double-quote key), the browser falls well short of the Sidekick’s, the lack of network storage means I’m reluctant to trust myself to put a lot of data on it, and the UI is uninspired. So I’m quite eager to see what Android, which represents the next generation of thinking of the key figures of the Sidekick team, is going to be able to do for me. But I don’t want to return to T-Mobile (and I need AT&T for our corporate plan anyway), which means I’m going to be stuck waiting.

On another note, I’m wondering how many Android developers will choose to put the back-ends of their applications on Google App Engine. Browsing around, it seems like developers are worried about exceeding GAE quotas — everyone likes to think their app will be popular, and quota-exceeded messages are deadly, since they are functionally equivalent to downtime. GAE also requires development in Python, whereas Android requires development in Java, but I suspect that’s probably not too significant.

I haven’t really seen anything on hosting for iPhone applications, thus far, except for Morph using it as a marketing ploy. (Morph seems to be a cloud infrastructure overlay provider leveraging Amazon EC2 et.al.)

Hosting the back-end for mobile apps is really no different than hosting any other kind of application, of course, but I’m curious what service providers are turning out to be popular for them. Such hosting providers could also potentially offer value-adds like mobile application acceleration, especially for enterprise-targeted mobile apps.