There will always be a glitch or something that needs taken care of. Essentially once all of the glitches have been smoothed out and taken care of, yes, I believe they can come up with faster technology. Apple should have the ability to provide fast service, as they do make enough money to invest in the science and coming up with the technology.
When a new piece of technological equipment becomes available, it must be better. It must run smoother, better and faster; even if it is just a small amount. Apple is known for vastly improving on its products each time they release a new model, I feel that the new iPhone will prove to be much of the same.
Apple's new IPhone6 is believed to run at 2Ghz while still using dual core technology from it's previous models. The phone however is also believed to have 2Gb of ram on board, instead of the 1Gb standard with the IPhone5. The previous Apple IPhone 5 processor ran only at 1.3 Ghz. These hardware improvements coupled with the A8 processor could possibly double the resources available making the IPhone 6 much faster than any of its predecessors.
It is my opinion that no matter how much Apple has improved the technology for the new iPhone, they it will not be noticeably faster for the average user. As with all electronics, the more programs, or in this case apps, that are installed on it the slower it will be.