I've been experiencing one of those periods lately where I've been really productive, I liken it to cricket when a batsmen is in good form. A number of factors have contributed to this, things like Tech-Ed and the fact that I have had a number of deliverables due. Just like cricket I think you go through periods where your form can slump when the conditions around you stay the same. You might still have lots of things going on around you but for what ever reason you just can't seem to clear them.
Tech-Ed was a big influencer in my recent good form, I had the same effect from the Tech-ed previously, its really good to interact with a bunch of passionate people. Now it seems that I wake up in the morning keen to get into some code, the funny thing as well about being in form is that the solutions you come up with often leave you wondering where they came from (in a good way).