Wi-Fi hotspot support is included, and this is another feature that completely changes the overall use of the phone, especially if you're a laptop/Wi-Fi iPad user.
It's a simple thing to set up: turn it on, change the name of the network and the password you want to use, and you've got a fully-fledged Wi-Fi hotspot to play with.
Of course, if you use it regularly it's going to eat up all your data, and connection speed is dependent on your 3G signal. But if you need a quick bit of web access on a larger device, then this can't be beaten as an option.
Flash video is included by default with Android 2.2, and while the HTC Desire could manage it anyway, the new 10.1 build is much more efficient, and is able to play Flash video natively in web pages.
However, we do miss the way HTC used to play the video on the Desire, as a double tap on the Flash file would take it automatically full screen. This is an intermittent feature on the Desire, so it's hard to work out how to use it at times.
Accessing things like BBC iPlayer is much easier now. Even though you aren't able to use the full version of the site (it defaults to mobile version) the overall feel is slick – despite not being able to download videos.
Install to SD card
We're still yet to see the full benefits of being able to install applications to microSD card, but there's no doubt this is going to be a very beneficial feature in the future.
Understandably, given there are very few phones using Android 2.2 in the world today, there aren't many applications written that make use of the new feature. But for developers this is a big deal, as they can finally flex their coding muscles and make some much larger and resource-hungry applications.
Other little additions – like including a Flashlight application and the ability to share applications with friends as standard – are all great things to have, and help make your HTC Desire feel like a new phone.
Overall, Android 2.2 is a real boost for the HTC Desire, which was already a great phone in its own right.
Battery life is overhauled, video is (somewhat) improved and the Wi-Fi hotspot addition is really nice.
It's a free upgrade too, and once the networks pull their collective fingers out and offer the update to all users (as well as putting Android 2.2 on newly sold HTC Desires), then the popularity of the phone will only increase.
We've only been playing with this for a few days now, so we'll be overhauling our HTC Desire review in the near future so you can see how it really will change your phone.