I wasn't aware there's definitely no more Torchwood. Last i heard was that Russell T Davies had series 4 'ready to go' if "Children of Earth" was received well. I've had a quick Google and rumours abound with a possibilty of series 4...tho what they'll do with it is anybody's guess.
I know some of the cast felt cheated because the series was only 5 episodes long, but screening them across one week was brilliant!!
As for Dr Who, i loved Christopher Eccleston doing it, but David Tennant is fantastic. He looks like he's so thoroughly enjoying it and he will be a big miss. It was announced last year that for his last year there would be four specials instead of a full series (maybe to accommodate his other acting commitments?) . Two of them have already been screened and i believe next one "The Waters of Mars" is on the weekend of November 14/15.
The last one has been finished and will be a two-parter shown at Christmas, bringing back John Simm as The Master.
The next Doctor will played by Matt Smith, who is the youngest actor to play him at only 26. I think he really has his work cut out for him, as it's such a complex charactrer and following David Tennant won't be easy!! But as Marwel says, change is the nature of Doctor Who.
I'll certainly give the new series a chance, though it won't have the same attraction!
I think Doctor Who may lose a lot of female fans once the last David Tennant episode broadcasts.