[The Dell Streak features] A customized multi-touch version of the Google Android operating system that features Dell user interface enhancements
The device is not yet available, but when it arrives it’ll be running the older Android 2.1. An OTA upgrade to 2.2 is said to be in the works for “later this year”.
This is what Android has wrought. To differentiate their devices from others running the same OS, manufacturers must implement custom interface tweaks. It becomes an issue with Android upgrades because the manufacturer must ensure their custom tweaks, as well as the hardware, work properly.