Isn't it true that no wide or normal length prime lenses--neither old nor new-- will autofocus on a D40?
First of all, no- it's not true, but the only new normal Nikkor prime to date is the 60mm Micro. As Nikon replaces its old primes, it's making them AF-S- prior to the 60, the 105VR, 600VR, 500VR, 105VR, 300VR and 200VR were all upgraded- though the 105 and 200s are the only ones that weren't already AF-S or AF-S II. Given the quality of the newer zooms though, and relatively static prime market, there's no telling if Nikon will replace all the old primes or not- which is likely why the shorter focal lengths are at the end of the list- the focal lengths are covered by multiple zooms of sufficient quality for most pros, and most consumers are covered by the kit lenses and aren't likely to purchase in the same focal lengths.
In terms of a D40 buyer though, the only other Nikon primes in the normal price range of the target market is the 24mm, 35mm and 50mm. While the 50mm lenses are a bargain- they're not all that profitable, the 35mm is the "normal" angle of view for a 1.5x crop factor body. The 24mm isn't a stellar lens at all IMO- I doubt that other than aperture there's anything it does that the kit zoom doesn't do- and it and the 28mm simply aren't "wide enough" on APS-C. Given that, I'd expect the 35mm to be about the only real candidate, though I suppose they may see a 50mm as interesting with the FX offerings, though it'd probably be better to see a new 14mm that works well on digital, as the $1700 current offering gets bad reviews on a digital body, but that's outside the price range of most D40 buyers anyway.
Sigma offers a (new) 50mm/1.4 HSM, and 30mm/1.4 HSM, 10mm HSM fisheye and 4.5mm HSM fisheye which should pretty-much cover a D40 or D60 user who wants wide but doesn't want to use the kit lens for it. These days ultra-wide on APS-C is a zoom- either a 12-24mm or a 10-20mm. The Nikon 12-24 is AF-S and the Sigma 10-20mm is HSM, so the only issue there is price- typically if you're getting a D40 or a D60 it's because (a) it's your first DSLR and (b) it's cheap. By the time you outgrow the kit lens in (a) you'll probably be ready for your second DSLR. If it's (b,) then you're probably not going to get a bunch of lenses soon either.
If not, try Canon.
