In general, having become accustomed to the US sucking up to Pakistan we tend to view such words as a sign of hope that the US may change its 60 year old policy of assisting Pakistan. It is so easy to read Mullen's warning and shout with joy and triumph
In general, I agree with you.
Pakistan lives on this kind of brinkmanship and has become reasonably good at this, for short term results. The US, which shares little in terms of strategic goals with India, will again reward Pakistan for bad behavior.
One observation from the local chaiwallah, was that we Indians were surprised after 26/11, to see how well the Pakistanis had war-gamed all of the possible consequences for steps that India could take. In spite of having Kasab and a fair amount of evidence, against Pakistan, in the end, India did back down from all its demands around 26/11 and did indeed bend over backwards for "peace" on Pakistani terms.
Note, the only discussion on Kashmir now seems to be focused on the status of the valley, while Pakistan overtly supports the JeM and LeT, gives up control of PoK to China, with India making little mention of PoK. India also goes out of its way to guarantee that bomb attacks in India are completely dissociated from Pakistan. The Samjhauta farce has also been explicitly brought into play, to reduce any implications of Pakistani perfidy.
Have you seen any Canadian, British or US elected leader visit and speak to key faction leaders in PoK in recent months, but they have all visited the valley and held independent talks.
It is in this context, the present brinkmanship has to be seen - Pakistan will raise the bar on this and escalate for a few more weeks, before actually compromising, with some thing on Kashmir or India-specific thrown in, to guarantee a face saving exit for the US from Afghanistan.
Expect the results of this approach to start showing up from some-time early next year onwards.