I don't think it would work. Everyone would spawn with Spartan Lasers, rockets, or snipers. I don't have a problem with power weapons placed on the map. It gives something to control and gain advantage. Problems arise only when they give too much advantage, as demonstrated by the dual wielding fiasco in Halo 2. Halo 3 was better in this regard.
Of course, Halo CE was best of all here IMO. Every weapon was useful in the right circumstances, and there weren't really any redundant weapons. The fact that Bungie keeps making a point of this when talking about Reach is an encouraging sign I think.
That can be worked around by a) leaving power weapons at objectives (i.e. obtain an objective/capture point get access to a new weapon) and b) limiting the load outs--even total weapons available.
The last point is pretty much what Halo does already: you spawn and everyone makes a made dash to the rifle and nades. Why not have a "armory" center in the home base? Much better than a Spartan Laser spawning ... on a grassy knoll???!!!!