SparkFun doesn't show the Teensy T_3.6 or T_3.5 yet - They have NO T_3.2's - but they are expecting a big T_3.2 shipment:
We estimate having 2419 additional pieces available
Typically Sparkfun puts their new products out on Friday, and they have a little segment on the new products. IIRC, Sparkfun only started selling the prop shields only in the last few weeks.
As I mentioned, Adafruit tends to cluster their new products around Wednesday with an announce on the Ask an Engineer segment (they went over this week, and didn't discuss the new products). Generally, Adafruit doesn't list stock counts until it is under 100. The 3.6 does not list a stock count. The 3.5 listed a stock count of 96 earlier, and it is now 92.
I don't see any 3.5/3.6's yet at Microcenter, which is one of the two places in the Boston area that sells Teensys in a brick and mortar setting.
You-do-it's website is completely useless. It is impossible to see most of what they carry from the website, let alone an indication of whether they are sold out. The website is supposed to be redone in November. I suspect that You-do-it gets their stock from Sparkfun and/or Adafruit, so it may be a while yet.
One vendor (Sports Internet Solutions LLC) looks like they will be selling the Teensy 3.5 and 3.6 and are expecting stock on October 8th, but with a $7.70 markup, even with prime shipping, it would be better to go to PJRC directly.
When defragster mentioned about the index.html page, I went to the pjrc.com page, it would be nice if
http://www.pjrc.com listed the newer Teensys on the front page (3.1 is the last teensy mentioned on that page, and it is now out of stock (permanently). And the Teensy pinouts page doesn't yet have the 3.5/3.6 on it. I realize the PJRC.COM staff has been going full tilt with the kickstarter and release, and need time to decompress, but it may be helpful when everything gets back to normal to to go through the web to make it a little more friendly to newbies. I always hate doing the documentation part, but it can be a necessary eveil.
It may be time to delete the MP3 player and 8051 development board from the PJRC store.