This episode is most definitely filler. I felt like watching it due to the rest of s2's brilliance - (School Reunion, The Girl in the Fireplace, The Impossible Planet/Satan Pit, etc..) - however, I was left with sheer disappointment. In short, Rose and the Doctor arrive in the then-future time of London 2012. Coincidently, children are disappearing into thin air ( yawn,yawn) . Turns out there's some kind of alien energy (?) and then Rose gets attacked by a hoard of mid-00s crapfest cgi - then the rest is probably "spoilers" - even though I firmly doubt there's anything about the plot to spoil. Basically, what happens is a whole lot of rubbish which has literally no real consequence in the phenomenal two-parter season finale. There wasn't even room for brilliant Russell T Davies era foreshadowing (see end of Gridlock S3), but as he didn't write it and the writer is clearly clueless, any worthwhile aspects were diluted and pointless. This episode's only redeeming aspect is the chemistry between Tennant and Piper which is great as always- but the episode overall is a degrading bore.
