Worthy of mentioning is probably Accusim 1.1 update video since it mostly deals with Spitfire (with some P40 teasing):viewtopic.php?f=77&t=26794
(That thread also contains download link to the update if you haven't installed it. Accusim update is for Accusim only.)
Also worthy of mention, Spitfire propeller tutorial video:viewtopic.php?f=77&t=23539
Due to nature of global announcements disappearing when they become outdated (unlike forums which are accessible in proper section), this link will be to the video itself, not the thread:
A2A Simulations Development Update Oct 2010:http://www.youtube.com/watch?feature=pl ... KfU#t=209s
Mostly Spitfire stuff, especially after 03:30 mark. This video was released before the plane was released, and the plane is beta (MkII with electric starter, something that didn't exist in reality).