Sorry to hear that eshodgson. Hopefully there'll be some progress for you soon. It does seem unusual for a six month processing on the UK visas. Something somewhere has fallen down and I just hope it can be sorted out quickly!
I'm starting the process now with my wife and I'm hoping we are within the 2-3 month period. I think I have a bit more patience for it though because when I moved to the US I had to wait 12 months for my Visa and that wasn't with any kind of guideline or estimate. It was just 'when it's approved, it's approved', so we were literally lost on when it would be approved. There wasn't actually a way to contact them and gain a straight answer either.
We had to contact our state senators. One of them didn't even respond to us, but the second had their office pestering the USCIS for a response and within a few days after that it came through as approved ... suspicious! But they won my wife's vote in the next election :p