Obviously they' ll need to tone the Pistol down a little, but as long as they don' t downgrade the weapons too far like in Halo 2 - which felt like you were forced into dual wealding when you shouldn' t have needed to - then I won' t mind if it' s like Halo 2 all that much.
Well if you play with professional style settings it' s a lot different.
Start out with BR: gives you a fair chance against any other weapon
Usually pick up smg or some other single handed weapon if you come across it for backup or you can duel wield it with something else which makes a pretty good fight in close range making all of those weapons actually have a use (besides needler).
Shotgun is an excellent close range worth picking up.
Rockets of course are worth picking up but don' t totally dominate because they shoot slower.
Sword is awesome for close quarters battle, it really isn' t as powerful as people make it out to be but still quite powerful.
Snipers are obviously is the weapon to have at long range (even mid and close range if you' re good enough)
Covenent Carbine is alright, good for if you run outa BR ammo.
So there you have it, every weapon (besides the needler) has good use and make up for a balanced game as long as you are playing on an indoor map. For the big outdoor maps duel wielding weapons are pretty much useless.
You have just been lectured on weapon balance.
Having actual uses for all of the weapons and each weapon have certain advantages over the other weapon for certain situations (like having a shotgun at close range is better than a BR).
I really doubt they' ll bring back the old Halo 1 pistol unless they have an option to use the whole Halo 1 weapon set (even though it sucks).
My prediction for the AR shown is that they' ll have it as a weapon in Halo 3 but make it a lot better than it was in Halo 1. Probably have a range a little closer than the covenant carbine and be about as effective as dueling SMGs except with better accuracy and longer range.
I' m guessing they' ll bring back a lot of the weapons from Halo 2 with about the same attributes only slightly modified. They' ll probably make the needler even better.