The biggest flaw has been the Doctor/Companion relationship- the whole fanficcy/slash dynamic is annoying as all hell. So, knowing that the last two episodes are a two-parter, and knowing that Rose is going to die at the end of this season (which they make a big deal out of in the intro this time), I have some optimism for the future.
From the previews, I knew Cybermen were coming, and I couldn't help but hope they did it better this time- the Cybermen plot this season was okay, but there was a bunch of supporting stuff that crapped all over it, and really kept the Cybermen from being too threatening a villain- compared to last season's Daleks- well, there is no comparison.
They do a really good job building up suspense through the whole episode, despite knowing Cybermen are coming. There's this mysterious "Void Ship" that appears in the episode, and circumstances lead you to believe it's related to the Cybermen invasion. But when the Cybermen are actually revealed, the Doctor asks them: "This is way beyond your technology- who helped you build it?"
The response was basically: "We have no fucking clue where it came from. It's not ours, we just followed it here."
At the same time, the "Void Ship" is slowly opening, leaving you to wonder what is about to pop out- and it's....
Next episode: Cybermen fighting Daleks. This is like asking, "What if Kirk and Picard got in a fight?" "What if Data and Spock got in a fight?" This is Doctor Who nerdgasm, on par with Babylon 5 and Star Trek duking it out.
I'm very much looking forward to next week.