Vodafone says it's an “an Android platform update to Gingerbread 2.3″ although, as the Desire S arrived running 2.3, this is more of a bug-fixing little change. Here's the explanation of what's different:
A new maintenance release for the HTC Desire S is now available to our customers. This update is an Android platform update to Gingerbread 2.3 and introduces a number of fixes and improvements, including:
When receiving an SMS the sender is displayed correctly.
Uploading of pictures using Peep (Twitter for HTC Sense) improved.
Desk Dock mode support added.
Call stability and performance improvements.
Vodafone goes on to say this is another of the odd two-stage software updates, where the phone requires one initial update to enable the second, just like in the good old days. And this is the phone itself. It'll still look the same externally:
The Desire S is a very lovely phone. We did a review a while back. Liked it very much.
source: Eurodroid