Will Apple's (AAPL) next iPhone software update -- the 3.0 software due this summer -- give iPhone developers a chance to make better mobile video apps?

So far, they've been a mixed bag. For instance, Sling Media's new SlingPlayer app sounds neat -- stream the video from your home TV to your iPhone -- but it's crippled: It only works via wi-fi, and not AT&T's (T) 3G network.

Why not? AT&T admits that its often-pokey 3G network can't handle the app's bandwidth requirements: "Slingbox, which would use large amounts of wireless network capacity, could create congestion and potentially prevent other customers from using the network," the company said in a statement.

It's possible that AT&T is just saying this to keep bandwidth-intensive video apps off its network, which don't provide any additional revenue to AT&T but do provide additional cost. But it's also possible -- we don't know -- that Sling just didn't make a very efficient streaming app. Streaming video apps, so far, have been mostly improvised, as Apple hasn't provided official streaming video support in the iPhone operating system. So we assume they're not as bandwidth-efficient as they could be, which could be why AT&T is keeping them off 3G for now.

But that'll change in a few months, when the iPhone 3.0 software rolls out. Streaming video support is one of the bigger new features, and it's possible that Apple will make it bandwidth efficient enough that AT&T could deliver more video over 3G without burning down its cell towers.

In the meantime, many video apps -- especially those designed for longer video clips -- are stuck in wi-fi-only land, such as apps from Joost, CBS's TV.com, and CBS's March Madness live streaming app. Others, including MLB's At Bat and the built-in YouTube app, do video over 3G, but short clips. And we've heard that Hulu's forthcoming iPhone app will work over 3G, but that is, of course, subject to change.