How do you know? Have you seen pics already? I assumed Hot Toys had their own booth.
No as far as I know, Hot Toys' representation at Comic Con comes through distributors, like DC's booth should have the Dark Knight stuff, Sideshow pretty much everything else.
Sideshow has the ALIEN, SENTINEL and WOLVERINE listed. The Sideshow site's coverage page for SDCC has a layout of their area with what products will be at what podium and the only podium without a listing is a special Stormtrooper pedistal, every other product is documented where it'll be on display.