For weapon master, maybe they mean Kensai? I dunno... as far as exotic weapon masters go, I really really enjoyed in the preview for 3.5 that dragon did, they rolled out a bunch of Alternate classes for the main base classes. One of which was the exoticist, and basically, gave up their proficiencies in all martial weapons for cherry picking 3 exotic or martial weapons, and also lost the use of heavy armor I think. Then, they progressed as a normal fighter with feats and such. This, multiclassed with something like the paladin or cleric made for some most excellent fun. The same issue had alternate paladins like the incarnate which traded in his lay on hands for a magic missile elemental type attack that was pretty amazing.
I believe they were both in issue 310. It is probably my favorite/most used issue of Dragon ever.
Aside from Prestige/Master classes and such, one of the things that always sold books to me were the variants of base classes. It didn't have to be a whole lot of new material, just different ways to play the same classes. Like, taking out your ability to wild shape or turn undead and instead give them... feats or spells or ranger abilities or what not. It allowed you to customize your character that much more. They had them a lot in the race books where certain species had special replacement powers because of who they were. And of course, in the Unearthed Arcana book.