Moved my gear over to nikon so I can share lenses with my girlfriend so I've now got the following:
D300s with MB-D10 battery grip (official one, both brand new)
Nikon AF-S 28-70 F2.8 (FX) = nicknamed the beast by reviewers due to how big the thing actually is. Its built like a tank and the sharpness on it, even wide open, is nothing short of outstanding. Its just had a service on it and been fully cleaned so its like new

Nikon AF-S 300mm F4 (FX) = Solid metal and tac sharp wide open, already love it
Nikon AF-S 18-200 F3.5-5.6 (DX) = nice general purpose lens and fully weather sealed
Sigma 12-24 F4.5-5.6 EX DG (FX) = Barely had a look at it atm but even on a crop its very wide.
Also got an SB900 flashgun and I've been learning how the commander mode on the nikon bodies works vs the canon ST-E2 system which I'm very familiar with. Seems pretty damn straight forward though!
So far, best thing about switching is the better AF system compared to what I had (canon 5D mk ii). It's not perfect by any stretch, but it does make some things vastly easier, like wildlife for instance if you want to frame it right instead of cropping to frame it in post. Worst thing is the ISO difference, which will negate itself when I jump to a D800 when the problems are ironed out with them, probably later this year/early next year. Use to routinely shooting at 4000-6400 iso on the 5D mk ii without it even breaking a sweat, yet this struggles with anything above 1600 judging from my early use findings.
I'll put some pictures of some of the kit shortly!
I can safely say after using both systems though, that both give stunning images, regardless of all the technical garbage thrown in. Each camera body I use just makes a different type of photography easier, from better autofocus accuracy for wildlife to quickly switching between preset modes to do a completely different style of shot in one turn of a dial. Now that the 5D mk iii finally addressed what everyone whined about with the mk ii (AF), things are definitely on a level playing field now in terms of bodies anyway.