The new iPhone OS 4.0 release yesterday is still being digested by wireless geeks, but it seems to execute a number of outstanding warrants for key features that the iPhone has been missing.

Ross Rubin, executive director of industry analysis for the NPD Group, says yesterday’s preview certainly made happy campers of a lot of iPhone devotees.

“They certainly answered a number of outstanding user requests,” Rubin says, noting that many of the new features that were demonstrated seemed to be aimed at “increasing efficiency and reducing the number of swipes or screens needed to get information.”

But Rubin says that while a system like folders will help with organizing information, it also hides information. 

“The folders idea highlights a dilemma… Now you have apps that are a layer deep in a hierarchy and it sort of runs counter to some of the things we’ve seen from HTC and from Android to bring that functionality up to the top of the UI,” he says, adding that widgets might be one way Apple will deal with this in the future.  

To be sure, Apple’s multitasking was the highlight of the day for end users. Will that feature, which many believe will drastically increase data traffic, have a negative effect on AT&T’s network performance? Rubin seems confident that the carrier is preparing for not just the enhanced iPhone but also the iPad. “AT&T recently announced a billion dollar capital investment in the network and it has a roadmap for adding capacity,” Rubin says.

But for all the enhancements to the iPhone’s overall UI, Rubin says Apple’s new iAd service could be the sleeper feature of yesterday’s preview.

“While users aren’t necessarily excited about new ways to get advertisements on their phone, they are interested in more functionality and are reluctant to pay for it. So, to the extent that that ad network allows for the flow of new applications to continue, then that really benefits the platform,” he says.