Didn't think the Raspberry Pi could get any better? You're in for a big surprise! The Raspberry Pi 2 Model B is out and it's amazing! With an upgraded ARMv7 multicore processor, and a full Gigabyte of RAM, this pocket computer has moved from being a 'toy computer' to a real desktop PC
The big upgrade is a move from the BCM2835 (single core ARMv6) to BCM2836 (quad core ARMv7). The upgrade in processor types means you will see ~2x performance increase just on processor-upgrade only. For software that can take advantage of multiple-core processors, you can expect 4x performance on average and for really multi-thread-friendly code, up to 7.5x increase in speed!
That's not even taking into account the 1 Gig of RAM, which will greatly improve games and web-browser performance!
Best of all, the Pi 2 keeps the same shape, connectors and mounting holes as the Raspberry Pi B+. That means that all of your HATs and other plug-in daughterboards will work just fine. 99% of cases and accessories will be fully compatible with both versions
Please note: The new processor on the Pi 2 means that you will need to update your existing SD card or create a new SD card with your operating system (Raspbian, Arch, XBMC, NooBs, etc) because you cannot plug in olderscards from a Pi 1 into a Pi 2 without upgrading with sudo apt-get upgrade on the Pi 1 first.
Also, any precompiled software will not work at full speed (although supposedly the processor will be able to run it). Still, you'll likely want to have it recompiled for the new processor! For many people, this isn't a big deal, but if you have a pre-created Pi 1 Model A+B+ card image, just be aware it won't work without performing an 'sudo apt-get upgrade' on the older Pi 1 before installing on the Pi 2!