If you want to gain some insight with regard to company product and design, listen in on the next CC. Nothing more than a mouse click these days.
However I believe that the GaN HFETs have better electrical characteristics at higher frequencies when compared to GaAs and LDMOS. This would eliminate the need for additional compensating, boosting or correcting circuitry. This also translates to a smaller footprint on the circuit board, which translates to an "X" amount of cost savings per unit. This in turn translates to improved "Y" profitability per unit since GaN HFET allows RFMD to eliminate the components (resistors, capacitors, etc.) that went with that additional circuitry.
Circuit board real estate is everything when talking about cell phones and the additional space could then be used for more memory, HDD storage or for larger cpu's with more processing power. Video phone! Apple, NOK and others are all racing to build better, faster, cheaper phones that will have built in apps for Sirius radio, ESPN sports, Navigation, as well as your favorite trading software. Yes much of this is available now, but it's not hit the affordability sweet spot for the masses.
The GaN material itself is an extremely durable material (more so than GaAs and LDMOS) which is better suited for harsh environments and environments with extreme temperatures such as outer space and deserts. Additional markets can be explored or improved in the areas of satelites, areospace, radar, and military communication systems.
Hence the excitement of GaN...
Course I could be all wet as this is only an educated swag. With regard to this rfmd, I bought the chart when it went into a tailspin down to the low $4's. Had been watching it for awhile and had been waiting for a nice correction to get in.