Sorry if this has been discussed already just wanted to throw this one out there. Not sure if ubi have mentioned anything as i've just found out they are making this game tonight.
For sure a UK sub campaign would be difficult as they on the whole did'nt seem to be as advanced as the german uboats but i'm sure it would be a challenge that many people would be willing to accept. :-)
Personally think it would add another unique aspect to the game as it has'nt been done in the previous SH games. If it is too late to put it into the final version, surely this could be a good idea for an add-on after release.