According to an official response given by HTC, the Gingerbread lineup presented at Mobile World Congress 2011 in Barcelona will be running on Google's Android 2.3.3., aka. Gingerbread.
It was pretty strange back then that the new version of the Android, the 2.4 one, will simply be called Gingerbread. It looks like Google stepped up to fix this confussion stating to HTC that the correct version number for the new Android Gingerbread will be 2.3.3.
A lot of sites have jumped the gun as this came directly from Google and it looks like that even manufacturers were told that the new Gingerbread will have a 2.4 version number. After all there were some screenshot of devices running on Android version 2.4.
We'll just have to wait and see and until then we can simply call it the new Gingerbread.