1) Not only a prettier Linux environment, but prettier Linux hardware. If a company sprang up based around Ubuntu that operated like Apple Computer in terms of providing a unified hardware product line and shipped Ubuntu with guaranteed 100% out of the box driver support for everything in that intentionally limited hardware range, and made the hardware appealing and sexy instead of standard economy PC fare, that would go a long way.
2) Integrated rootless virtual machine support for running Windows or Mac apps side-by-side with X apps. Integrate something free like VirtualBox so that any user can quickly and easily install Windows or Mac OS X and fire it up in rootless/seamless mode.
3) A real shareware economy. What makes the Mac so great is that there are countless $20-50 apps that work really really well on scratching some specific itch and the Linux desktop is completely missing that. Open source doesn't always address my needs and can't always do that. Would be nice to have this kind of focused, for-pay community software available on Linux.
The RoadHEAD. There's nothing flappy about this transmission. Speed is continuously variable and changes are initiated by voice command. Transmission makes all the right noises right up 'til redline, where it becomes a real screamer. While cars equipped with RoadHEAD have a spotty safety record, we stick by our slogan: RoadHEAD, what a way to go (go, go!).
An expert in vim can accomplish his task far faster than an expert in any other text editor.
Close second would be Emacs with viper mode, but if you don't need the programmability of Emacs then it's weight and speed can slow you down.
A real embedded vim InputManager for Cocoa would rock so many worlds.
I once horse traded a tiny window unit air conditioner left by the previous tenants of the centrally cooled house I'd just moved into for a white 1972 Chevy LUV with what hot rodders call a nice "patina". I rewired the "bad" alternator in the dude's front lawn (it wasn't bad at all, just wasn't wired correctly), jumped it, and drove it home. Had it for 2 years as a parts getter for my daily driver Datsun 720. Anytime the Datsun was in need of repair I'd fire up the LUV and off to the parts store I'd go. Loved that truck. It had 4 on the floor and a scrappy little Izusu 4-banger with a manual choke on the carb. I'm sorry I finally got rid of it, but the high price of scrap steel was too tempting one month when I needed to pay a bill.
I personally like the '63 and '64 Rivs the best. Here's one I caught Down At The Staples recently.
Junior Brown has a thing or to say about Redheads and Rivieras.