I did feel that it was a bit short - maybe even a bit lightweight - at forty-five minutes, though it managed to cram a lot into the time it had. I wouldn't want to go back to the pace of the older series, which is unfortunately just too slow to compete as modern television, but I reckon the two-parters that make up some of the rest of the season have the potential to be more satisfying - and, of course, include a proper cliffhanger!
I was a bit surprised to note that Doctor Who Confidential wasn't plugged straight after the broadcast, so let me do so now. There are half hour programmes about the old series and the making of the new series being broadcast immediately after each new episode, over on BBC 3. Assuming you have access to BBC 3, it is probably worth switching over. They're being narrated by Simon Pegg, fanboy and star of Spaced and Shaun of the Dead, who also appears in a later episode of the series himself.
Watch out, too, for a new live performance of The Quatermass Experiment next weekend on BBC 4 shortly after Doctor Who Confidential ends. That should be very interesting to watch on a number of levels.