Brian has put a very teasing message on his website to the effect of him and Rog doing something, maybe they given out an award to somebody unless they really are doing a set?
If you click at the brit awards website, you will find an item about the brit awards compilation album. There is a bonus disc of songs under the contribution to music category and Don't Stop Me Now is the number one song in this bonus disc.
I think they will be there for this reason.
I thought I'd read that Blur were getting that 'contribution' award this year, and that Queen have already won it before? It could be a special '40 years' presentation like the MTV thing?