Hacx 2.0 is an in-progress team effort to improve and "finish" Hacx. It'll feature about 25-ish new and/or vastly improved maps, revamped enemies and textures, improvements all around. It's practically a new game, but one that will hold much truer to Banjo's ambitious original design documents than the "final" product that was eventually sold... and this time, it'll be a free standalone game from the outset. Huzzah!
For those wondering about the project's status, it's more or less always at "slow, but not abandoned." The resources and plans are in a slight bit of flux, but the industrious Cage is currently hard at work at completely revamping the game's bestiary to provide way more awesome stuff to shoot at (following which we hope to attract a lot more mapping interest). He's the one to thank for pretty much holding the project together and turning it into a Real Thing(tm) rather than a Xaser pipedream.
Check out the linked website (also Cage-produced) for a more thorough summary of the new content. It's way more interesting than this silly link-pit of mine. ;)