The thing is, if you would have told anyone the iPhone 4 was going to DOUBLE the resolution of the first three generations, it would sound unfeasible. But not only did they do that, but they also INCREASED battery life, made it THINNER, and added several other features. It's Apple, if Steve Jobs wanted to sell chunks of the moon, there would be a keynote announcing the iSky MoonStore.
Pixel doubling would be fantastic. Honestly, the A4 GPU COULD handle it with simply more memory. I had an old old laptop (I use it now attached to eSata drives as a file server) that was able to run a linux Distro at 2560x1440 on a Cinema Display, with a GPU that is MUCH slow than the A4. It's all about having the memory to do it. I suspect that GPU intensive software, like games, will use the same trick PC's have been using since forever, simply displaying some apps at a lower resolution! If the screen had the ability to change resolutions (like many monitors do!), or even if iOS had something built in, it could easily run iOS at that resolution, and games at 1024x768, on an A4. No telling what they could do with their own silicon.
As far as batteries, Apple is venturing into LiPo technology, and as someone who has used LiPos for a long time (R/C planes, some very big ones!), I can tell you that the technology is absolutely there. I mean, if the Macbook (white) can run for 10 hours on a power-hungry Intel CPU and a Power-Hungry ATi GPU, I think Apple could figure out a way to get 10 hours out of a battery-optimizes ARM processor/GPU architecture. I bet if I wired up a 6-cell R/C LiPo pack (would require some major voltage reduction, little over 24 Volts is a bit steep for the iPad), I bet I could keep the iPad going for 24 hours, with a battery roughly the size of the batteries that are already in it. I don't think Battery life will be a concern. The batteries are just so expensive, I would venture to say that Apple decided on a number (apparently 10) for the battery life, despite the fact that they could go much longer on similarly sized cells, but doing so would increased cost. Honestly, who needs more than 10 hours? There's an exception to every rule, but the general consumer can certainly get by with 10 hours, if not there is a solar powered device that keeps it running (doesn't charge it, but keeps it from discharging) all day long, not to mention tons of other accessories to extend the battery life.
Most of the current LEDs are simply LCDs with LED lights.
Yep, the term the other poster was looking for is "LED Backlit". LED screens like on LED TV's, now those are cool, but have you SEEN the cost? Not nearly enough performance gain to justify the cost on a mobile device, BUT, if they did, I bet they use less power, might be another solution to the issue of battery life on a beefy machine.
You know what though, just look at laptops. Both power usage AND battery life on laptops have both INCREASED over time (give or take, I mean a 2 year old MBP might use more power than a new MBP, but a new MBP uses a HECK of a lot more power than an Apple Portable, or a PowerBook G3, etc. yet it has tons more battery than those older devices). Point is, battery technology is growing as fast if not FASTER than the technology it powers. Battery life on EVERYTHING is going up, not down, yet the devices are getting smaller and lighter. That tells me that, in fact, battery technology is moving FASTER than the technology it powers.
