If so, and the new high res tech becomes available, should I wait till then to start making a map, or could I start making a map under, say, Clem's tutorial and make it high res later on using Oak?
Yes, Oak will come out with 1.7 when it is final. Yes, start making the map now and later make it hi res. You don't need to wait for it since it works with the map you are or have made.
its better to start now and make it look the best you can in 1.6. Since not all people will see the detail textures (its openGL only) the same colormapping skills are still needed, good luck with your map and feel free to post some screenshots...
