A spokeshave with a concave face works well for making shafts, and is quite a bit quicker than whittling. From my research, the old-timey fletchers used a similar spokeshave to carve shafts out of billets. But I do cheat and chuck the unsanded shafting into an electric drill (like a poor-boy's lathe) for final sanding and tapering.
As far as getting the arrow blanks out of a log, I think you are using bleeding-edge (I hope not literally) technology already.
Here's a link to a half-round spokeshave:
http://www.woodcraft.com/product/2000562/3975/kunz-spokeshave-half-round.aspxThe downside is that concave blades are a pain to sharpen and hone (none of those slick little honing jigs work), so I use a round diamond file to build the edge and switch to wet/dry sandpaper (from 400 to 1000 grit) wrapped around a paper-towel tube for final honing.
Hope this helps.
jack