I know some people have been hoping that SIR will be in the new Stitch attraction, but now I might be putting it to rest I read in the book Walt Disney Imagineering that they don't reuse AA's that people will recognise as such - SIR since he was a main character (the time they mention is when they closed America Sing's they took most of the AA's an put them in Splash Mountain but didn't use two because they were too recognisable). Though if you remember the Lilo and Stitch movie there is a spot for SIR which is right next to the chair woman which you see when Stitch says "alacrishta!" or something like that there's a robot right next to the chair woman who then throws up nuts and bolts who I think looks like SIR.
Pic: http://images.countingdown.com/images/countdowns/movies/260157/1011/539433_main.jpg
Pic: http://images.countingdown.com/images/countdowns/movies/260157/1011/539433_main.jpg