When the initial study came out concerning this, I took it with a grain of salt. With the amount of publication pressure that any researcher working in the life science academic group is under a lot of results get published prematurely and end up getting debunked later. The whole series of articles relating to foods causing/helping guard against various illnesses is a good example of what I'm talking about.
The question is: does low wattage RF radiation do any cellular damage at any frequency?
I doubt it. Besides, these tests aren't valid unless conducted with subjects who are completely isolated from all other forms of RF exposure (put out by commercial/emergency service radio, wiring in most homes, high voltage lines, the earth, the night sky, etc etc etc). I mean, if RF damages genetic material in the same manner that gamma radiation does, for example, then you should isolate subjects from all radiation.
I don't know if mobile phones cause any kind of disease, but it has been demonstrated that they somehow affect the quality of the sperm of men who wear their phone at the belt or anywhere near the genitals. The sperm count is statistically significantly lower and the motility of the cells is also reduced. This doesn't happen for men who have their phone in the front pocket of their shirt or have no phone at all.
These results are based on serious research, but the link between irradiation and spermatogenesis hasn't been clearly established. The statistics are there as a warning, though.