I'd really like to see the game play lean more towards BF2 than BFBC2.
For one, get rid of the tracer darts, bring back the rockets you had to guide yourself. RPG's should not be able to track a target. Make them have a slightly higher strength if need be, to counter those an engineer can guide.
Allow med packs/ammo packs to be carried around again or tossed if needed. Also bring back the instant healing/ammo recharge abilities of those packs, instead of the current ones where it takes forever to heal/rearm yourself. Not to mention the fact the one pack will supply everyone. One pack, run over it, instant heal/rearm, and it's gone.
Don't know how you're going to handle the defibrillators, but BF2 seems to have the right length of time to revive someone. BFBC2 had WAY too long a time to revive someone, and currently once you die here, it's very quick to re-spawn, so fast that you can't even select your base sometimes.
Add an option to choose where you spawn like BF2, make it available to be preset, in case you like a certain area of the map as opposed to others. The current system is too limited. Don't allow spawning on any member of your squad like in BFBC2, squad leaders are acceptable as spawn points as in BF2, but the BFBC2 system got annoying.
Please bring back the grappling hooks and zip lines to this game, it opens up the maps so much. I really hope you're bringing in special forces maps into this game, Ghost Town and Warlord were my two favorites.
I do like BFBC2's weapon customizations as opposed to BF2's, so you could implement some of those features.
Please to do not restrict height/area of space for your choppers and planes as you did in BFBC2. Those flying bathtubs were deathtraps. The controls and agility of things were like sticking wings on bulldozer and calling it an nimble aircraft.
Also bring back back the chopper pads/runways for self healing, that's a must. And if you insist on leaving in those damn tracer darts, at least don't turn off the chaff as you did in BFBC2. That so called unlock in BFBC2 didn't work worth a crap to break those locks and turning off the ability to discharge flares or making it an ability is like saying 'oh you wanted wheels with that car you have? That will be extra.'
I'm sure I'm forgetting a ton of stuff at the moment, but lastly I would recommend you guys check out the AIX mod for BF2, it was awesome. That mod had a ton of features and ideas that would work well I think in this game. Overall, good beta so far guys, you're doing better than some I've been in, keep up the good work.