Just back from town (Stafford).
Phones 4 U have WP8 PoS up, came in last night. They have dummy units of the 920, 8X and 820. The 920 is free from £36/month and available on EE, Orange and T-Mo. The 8X is free from £31/month and available on all networks (bar Three - P4U don't do Three). They said they should have units in by the end of the week, but don't have tariff details yet.
The two EE shops were a similar story. Not much in the former Orange shop - just empty spaces for the WP8 handsets (marked up, but no dummy units in place) and a couple of the new 4G EE handsets. The former T-Mobile shop had a massive display for the Lumia handsets... with the SGSIII and Note II sitting on it because they've not had dummy units for the Lumias yet.
Three, Voda, O2 and CPW hae nothing up at all.
TBH the exclusivity doesn't seem so bad if it's EE, Orange and T-Mo. Still annoying, but could be worse. Don't they already have over 40% of the UK market? 4G is only likely to grow that.