There is a lot of information about this wildcat cartridge over at this website. Do a search on 338-08.
http://talk.shooters.com/room_67/Nov142002.cfm
I read some of the posts last night as I too am interested in a 338-08. If I correctly recall, 180gr bullets were in the 2800-2900fps range and 200gr bullets were in the 2600-2700 fps range. One thing I did note which concerned me was the difficulty in finding dies for it.
This cartridge should not be compared to the 338mag. It isn't a magnum cartridge! If you want magnum performance, then by all means get yourself a magnum and accept the recoil and weight associated with that cartridge. But if you want to shoot bullets with a bigger frontal area and not have the recoil then consider the 338-08. What the 338-08 is, is a very effecient cartridge which functions in a short action allowing for lighter overall weight and giving you the ability to have a 24" bbl if you want without having the weight of a long action with a 24" bbl.
As for its ability to anchor game, read the thread on Shooters.com where Double D used this cartridge in Africa on many plains game that would equate to our deer and elk. That should sober some of the critics of this cartridge up.
That all being said, it will never edge out an established round like the 338 win mag or even the 338-06. But often when dreaming of a wildcat cartridge the impracticality of the logic justifying it is something one accepts.
I'm more than likely going to pursue building one. Might even have to have custom dies made. Do I need it, no. will it fill a empty slot in my battery, no. But I'm going to have one built just so I can say I've got one and that it will dump deer and elk like any other rifle I already have. Sometimes the reason why isn't really a reason at all.