For me, it all depends on value. If I see that Brees, Brady and Manning are all still left and I can get great value for them, I'm obviously going to take them. But normally I don't grab a QB until round six or later (McNabb normally lands to around round six, but if he isn't their, I'll grab Rivers, Cutler, Palmer or Big Ben much later in round eight or so.
Now for TEs, the earliest I'd take a TE is round five and that goes to Witten. If Witten is not available then, I'm going to wait and see what value I can get. I've also waited till round 9+ to grab a TE and I've landed Daniels, Olsen, Keller (who I'm extremely high on with a rookie QB).
A win next week and all is forgotten.