There is a measurable trend with computer components that broadly states that the processing power of integrated circuits will double every two years. Because this trend comes from the ability of manufacturers to pack more transistors into the integrated circuit boards, this same trend holds true with other components such as memory capacity and sensors used in making digital cameras. This trend was first identified in 1965 by one the co-founders of Intel, and has held true ever since.
Many of the advancements in mobile phone technology therefore stem from this ability to get a lot more processing power into the same space for a similar cost as was possible a few years ago.
For consumers, this means that the mobile phone you purchase today will become out dated within 12 months, if not sooner. It will of course continue to operate perfectly satisfactorily, although subject to wear and tear, until you decide you can justify the enhanced features of a new phone.
Of course there is a delay between the technological advancements and those advancements making their way into mobile phones. For this reason, manufacturers are constantly releasing information on their next range of mobiles, even though these will not be available for several months, and in some cases, for the most complex devices this can sometimes be as much as six or nine months.
This does give some idea of the paths in which mobile phone advancements are going.
In addition to higher resolution cameras and near high definition video you can expect to see mobile phones with huge amounts of memory to enable storage of images and music.