Well, it was mostly an idea on how to go around doin' it.
But since you've put it that way, yes. It's I think a good idea to make making changes with plugins as easy as possible.
Oh, how I wish the number of blocks wasn't limited by mc itself and that you could push graphic elements(mobs, blocks, item, gui) from the server to the client (stored on a per server basis to make sure a server mod doesn't break your game). Couple that with an easy way to create server mods (plain txt / xml for common stuff like mobs, items, blocks, gui; LUA for the more complex stuff like mobs AI, new items/blocks behavior)... well, you can imagine I reckon.
It's all very possible too, but mc was just written soooo baaaad. Oh well.