Your picture of the arch is a fine example of what can be accomplished but lets face it, It isn't exactly straight out of the camera.
It is far from straight out of the camera. I remember the first time I tried to shoot this from the otherside (in Washington Square Park). I just picked up one of the first copies of the Tokina 12-24 and went their specfically to shoot that and other compositions I envisioned would lend themselves to wide angle. I immediately realized the problem with that type of shot. Because it is impossible to move further back the only way to capture it was to fix in photoshop. FX may minimize this, but that unless I could be elevated to a height around the center of the structure, it will still look like it is falling backwards. A 14-24 and D3 is not going to change that, only reduce it. Anyway, that copy was soft and I returned it for the Nikon 12-24. That is not a perfect lens either and horizon lines can have a weird distortion. I do hope that Nikon will make a 10-24 f/4 DX nano-coated DX down the road.
Below is a shot of the George Washington Bridge shot at 12mm standing at the edge of the cliff on the wrong side of the guard rail. As you can imagine, this is far from straight out of the camera since I am about the middle height so the top, bottom and middle all did different things. This one took a lot of work making many different adjustments to get it to look natural. As you know, architectural captures require the best and right equipment (your major point), perfect capture technique in composing including perfectly angling the camera to the composition (many newbies to wide angle do not get this at first), and often plenty of PP work. Anything that minimzes the process is welcome
Hopefully this newfangled dust removal system will make changing lenses often less of a pittfall.
So far I do not think I had to wet clean my D300 but I have had to so this many times with my D200 and D70. But, dust will still be a problem. My nine month old D200 has a nasty dust spec in back of the viewfinder which drives me crazy and I have not been able to blow it out. So changing lenses is a still something I try to minimize