I'm kind of confused at this point as to what you guys mean when you say source blocks, and have been since Kama mentioned keeping some in a chest. If you mean just a normal one like the kind we can find in the wild, that wouldn't really help, since we can't place them yet. Is there some kind of "lava source" item that you can have in your inventory without a bucket that gets placed like normal?
I had assumed previously that whoever made the lava on Adisharr's building did a normal "point at block, spawn lava immediately" type deal like you can do in the console in most FPS games, but that still wouldn't be something you could carry around.
At any rate, just having an unlimited supply sitting there for the taking kind of takes the fun out of exploring. TNT is okay, since we have monsters turned off and no other way to get it; while non-admins currently can't place lava out of a bucket like normal, that may be fixed as of the Saturday update.
I guess I'd say either wait for the update to see if lava is fixed (and if it isn't, THEN create the pit) or create the pit now but destroy it if normal lava is fixed on Saturday.

