I started a thread recently on the BA Exec web site and asked a fairly simple question - "Does anyone KNOW if the BAA/UK one carry-on rule will be permanent". (As opposed to the "One carry on and one personal item" rule in almost everywhere else.) In my view, this is yet another reason to avoid flying through UK airports. There was no real answer.
I have recently flown through BSL, ZRH, MUC and LHR in Europe. LHR is the only one with the "One bag" stipulation, which of course is enforced by the spotty kids who harass you before you get to the security check.
The new pastime in the lounges now seems to be repacking your bags once you have got air-side into the more convenient "one-plus-one" manner.
Any info would be very useful.