The iPad really is a giant iPhone—so much so that if you want to get a laptop-like experience out of it, you'll need adapters to change the typical 30-pin connector into USB, SD, or AC power. Correction:
In addition to the keyboard attachment, there will also be dongles, attaching to the 30-pin dock connector, that give a USB port and SD card slot. In terms of charging, there's no built-in MagSafe connector or anything, so they'll also be shipping an iPod-to-AC cable as an optional extra. Correction: The 10W USB-to-AC cable will be included in the box, not an optional extra as I wrote earlier, in the heat of the battle (and Apple events are battles, at least for us).