Sony Ericsson's Xperia X10, which we first saw back at the start of November, isn't out yet, but the manufacturer has already begun promising firmware updates that bring the Android version up to 2.1.

In an extensive post on its product blog, the company responded to criticism that the device is coming out with Android 1.6, despite other phones already being out with 2.1. The upshot basically being that SE doesn't really care about OS versions - they care about the total UI package.

The company's Sumit Malhotra says: "I am not trying to hide from the fact that there are platform upgrades between android 1.6 and 2.1, if utilized can enhance the experience for developers and users. Having that said, I have had discussions with carriers that are very sensitive and concerned generally about taking on devices in their range that are not competitive enough".

"I have faced head to head comparisons between Xperia X10 and generic 2.1 Android devices (as well as other OS) and carriers have concluded that we still stand strong in comparison. This is because of the layer that we ad on top of the generic OS.

Interestingly, Sony Ericsson's product page for the handset now says "To be announced" under release date. A while back it was saying 10 February, implying a slippage in release for the phone. We'll keep you posted when we hear more about what's going on there.