We've already heard rumors/crazy-talk about iPad 2 having an SD card slot but now AppleInsider raises the bar with yet more purported case leaks from China, these showing what they think might just be a MiniDisplay port as well. The theory is the SD card slot would be an embedded version of Apple's existing iPad Camera Kit (without the USB adapter portion, of course), while MiniDisplay would replace the current VGA dongle much as it replaced DVI on unibody MacBooks.
While AirPlay is being pushed as the streaming video standard, if a 2048x1536 Retina Display iPad 2 becomes a reality (still a big if) with an Apple A5 chipset, a MiniDisplay port might be Apple's preferred method of pushing HD video over a physical cable.
The 11-inch MacBook Air has a MiniDisplay port and the 13-inch MacBook Air has an SD card slot. While extremely portable, and sometimes jokingly called iPad Pro, they're still traditional computers. iPad is meant to be a next-generation, mainstream computing appliance. Senior VP of Design, Jonathan Ive said there was nothing on the original iPad that wouldn't be used almost all the time by almost all users. Would Apple really go port crazy on iPad 2? Do you want them to?