Airbus A319
It is now apparent from the Aer Lingus booking system that the 319s will feature in the BFS plan for 2012, they seem to be operating on all routes at some stage except the canary islands from what I can see.
LHR seems to get 320 during the week but most weekend flight seem to be 319, making way for 320 on more holiday orientated routes.
There do seem to be times when an A320 is needed on LHR and at the same time needed on TFS, so it may be that there will be 1 x 319 and 2 x 320, but some have commented that it is to be 1x 320 and 1x 319.
My guess would be that some flight ex Dublin may need 319 eg some of the newly proposed routes that FR will also start, eg Verona. Stockholm well served by FR so this scandinavian route may be thin enough and EI previous experience in Scandinavia would be slack enough, so may be the case for a 319.
EI-BUD