Solar Panels may also be coming to future iOS devices.
The iPad 2 is really starting to shape up- at least in theory. It's "believed" to be set for launch somewhere between four weeks from now, and April. Some rumors have Apple acting as exclusive retailer for the first three months, while a near-retinal display and microSD slot have also been leaked.
Of course, nothing at all about the new iPad has been officially confirmed. However, Nexus404 reports that developers are being asked to submit two versions of their new apps- one for the iPad and one, presumably, for the iPad 2. Seeing this, we find that the iPad's resolution will be moving from 1024x768 to 2048x1536.
That's an upgrade in pixel density from 132 ppi to 260 ppi. Such an improvement necessitates an upgrade in processor speed and RAM. We've heard rumors that the next iPad will pack a new A5 processor, which is a multicore platform that could be roughly equivalent to something like the Tegra 2. It's also possible that we'll see a lesser improvement, maybe up to 1.2 or 1.3 GHz.
New patent filings indicate that Apple also plans to add a "voltage regulator" and "smart controller" to the new iPhone/iPad. These will allow future iOS gadgets to turn on and charge from an unstable power source, like a solar panel, without damage to the battery.
There are other obvious uses for this technology- most airports have rapid charging stations, and there are a number of portable batteries meant for burst charging. Apple may just be improving the iPhone's functionality with these devices. But this could also point to plans of adding in solar charging solutions to future iterations. That would mean a wild shift in Apple design philosophy, though.