I love ER too, and can't wait for it to return to our screens. It started airing last week in the US and I accidentally came across a spoiler as to who was on board the ambulance although if you think about it we already kind of know! Apparently it's really sad though so get those tissues out!
With regards to the whole Mark and Doug Ross thing...
It starts this Wednesday, BBC2 at 9pm with the second episode on BBC3 afterwards!