As this is my favourite Young Adult series since Susan Coopers "The Dark is Rising" series, coupled with how beautiful the last big fantasy BBC adaptation was ("Jonathan Stange and Mr Norrell"), I am quietly excited about this. The BBC has shown that it can produce consistent high-end production values over an 7-episode period and, with sound budgeting, I don't see why they couldn't pull off "Northern Lights" too. It's more down to whether they can capture the tone and spirit of Pullman's book.
I can see this being aimed at the Dr Who crowd, and given how complicated, and at times dark they have allowed the BBC to let that show grow into, the darker, more mature themes of the later novels should be no issue too.
Most important other factor - casting the right Lyra. So hit and miss are young actors that they can make (Haley Joel Osment) or break (Jake Lloyd) a production.
Hugo - speaks of destiny, knowing it is unfixed