Personally, I remain skeptical. I agree with SDB:
My opinion is that Taiwan is capable of defending itself against an invasion by China without our help, and with our help such an invasion would be hopeless. But we would not help with ground troops; our contribution would be naval and air. A hypothetical invasion of Taiwan would be won or lost in and over the straight of Taiwan.
The VodkaPundit counters that the PRC doesn’t have to actually invade, since they could lob missiles. This strikes me as a hollow threat, though. Any direct strike on Taiwan by the PRC would not only risk, it would virtually guarantee, war with the United States. The possible gains from striking Taiwan–which are almost entirely psychological–would be almost infinitely offset by the potential downside. And the Chinese regime has proven itself, if nothing else, rational in its calculations. Regime survival is their ultimate objective. War with the United States is the only real short or medium term threat to that objective–and an attack on Taiwan is about the only thing that would spark it.