Ok so we can pick up Arch as soon as cata hits but do certain zones have certain finds for your skill level the same way herb and mining works . Lower skill ups for ores and herbs are in lower level area's then as you level and skill prof, the higher skill stuff is in icecrown etc. Or do you find items in any zone dependent on your skill like fishing ??
i hope it works by finds are in any zone but dependent on skill as it would suck to log into cata ready to go from 80-85 but have to go back to
1-60 zones then outland then northrend to level this new skill
as far as i understand you collect fragments from digsites and after solving a project you got 5 skill points,you only have 4 digsites per continent (4 per kalimdor,4 per northrend,etc) and they are totaly random and goes up with lvl,so lvl 80 can get digsites from 1-80 zones,where lvl 30 will get 1-30 zones,so to answer your question ,yes you will have to go to all zones but also you can get digsites in new zones if you lvl up to 85
On my lvl 80 (beta) priest I went straight to northrend after learning Archaeology. I got skillpoints from surveying in Northrend sites immediatly. I went back to Loch Modan after ~10 points and tried there, and got skill points there too.
It seems a bit like fishing atm: You can survey wherever you want. The stuff you get FROM surveying (as in, the final items) will depend on your skill level.