Watching qualifying, I really like the circuit, and I hope Red Bull don't feel the need to extend it. Sure, it would be nice to see Sebring-Auspuff reintegrated into the layout, but I don't see how that could be done without killing the appeal of the circuit. There was the proposed 'Westerschliefe' extension that got a lot of positive reactions, but in retrospect, I think it added too many slow corners.
But I also think that there has been a trend towards complexity in recent designs, with circuits having twenty-odd corners and similar lengths. Sometimes, it works wonders, like Silverstone (the old Bridge complex was horrible, and didn't fit the spirit of the rest of the circuit), but other times, like the Nürburgring, it's terrible. The Red Bull Ring stands out for its short length and deceptively-simple layout, and I don't think that should be sacrificed for the sake of shoehorning one corner back in.