This all feels like the iPhone 3 to 3Gs transition to me. From my seat, NONE of the announced tablet alternatives (including Galaxy Tab 2, Xoom, Playbook, and Touchpad) beat the existing iPad, other than SD or microSD expansion support and built in video out. So what is Apple's incentive to substantially overhaul the iPad this year? From what I have read, a higher resolution screen won't be coming until 2012. They are likely to add some form of memory card support (likely SDXC), BUT that will not be like the SD card support on the Android and Windows 7 because Apple has not enabled a full file system for the iPad.
My money is on this time next year when Apple does an iPhone 4 type makeover of the iPad (liquid metal anyone?) with 2x video; Qualcomm chipset for universal connectivity; 128gb SSD option; mini-displayport; Apps run across the entire platform from iPhone to iPad to MacBook Pro.
So let it be written, so let it be done!