It’d be really nice to have a keyboard shortcut for strikethrough, as the only to apply it now is through the menu system. I think this exists on the Mac version.
BTW, thanks, Lee, for all the work you’re putting in.
I’ve added it to the wish list. It’s not an onerous task.
Lee
I concur about the need for quick strikethrough. In re-write mode, I use strikethrough when I want to eliminate a line, and still be able to reference the thought. Delete is too final. A menu bar button for strikethrough would be very helpful. Right now it’s right mouse click, font, then strikethrough, and it always seems to hesitate on the right mouse click, especially if you have a lot of fonts installed. This is still the best writing app available, with or without strikethrough.
I’d like to also (gently) third the wish for a strikethrough button on the menu for the same reasons sageimac mentioned. I picked up the strikethrough habit/method from NaNoWriMo (Never delete words! gasps!), and it’s sort of stuck. Having this would be like extra frosting on the cake. 
(Although, I don’t see the right-click option? I’ve always had to go to the Format menu->Font->etc. Am I missing an option?)