While still a revolutionary application development framework, Mojo has gotten a bit long in the tooth, and apparently, Palm sees no more room for improvement. As such, they've been working on Enyo, a reference to a Greek goddess of war (Kratos but with boobs, basically), which will give considerably speed improvements over Mojo, while also delivering several other noteworthy improvements.
First of all, it's been designed by the same people who developed Ares, Palm's browser-based IDE, so it integrates nicely there. It's also capable of handling multiple layouts at different display resolutions, very important since HP/Palm aims to put webOS on a lot of different device types. Palm demonstrated a conceptual email client running in Chrome running at a phone resolution - they then showed the exact same application running in a larger window, with a larger, tablet-friendly user interface layout.
Enyo is also a lot of faster due to, among other thing, reduced code complexity (Palm claims some applications go from a seven second boot with Mojo to just one second boot with Enyo). It's also object-oriented, has better event handling to eliminate memory leaks and "too many cards open"-errors, and has hardware acceleration built-in.
A developer preview will be released soon so that developers can get a feel of what Enyo is capable of. It's important to note that Mojo won't be going away anytime soon - they will just exist side-by-side, but considering the improvements Enyo promises to bring, you'd be a fool not to take advantage of it.
Enyo is ready for war. The webOS may have been off to a rocky start in the marketplace, but thanks to HP's infusion of lots of money and developers, it'll be around for a long time to come. HP is fully aware it needs new devices to draw the crowds, and the company stated that we'll see a whole bunch of new devices coming early next year. I can't wait.