There is a very interesting effort: the GTA04 mainboard for the Neo Freerunner smartphone. As you may know the Freerunner is quite oudated by today standards and also it has several design bugs which made it even more slow and annoying (unsuccesfull integration of the graphics accelerator or the well known problems with a deep leep mode or with the sound).
So guys from the Golden Delicious decided to make the new internals for the Freerunner. The result of their effort is called the GTA04 (the original freerunner was called the GTA02 by the OpenMoko and its cancelled successor was called the GTA04). The GTA04 is a new mainboard for the Freerunner so one will be able to keep the rest of yhe phone (a case, antennas, a speaker and a microphone and a display). Or it is possible to buy a complete phone.
The advantages are obvious: the hardware is much more up to date (an 800 MHz CPU, a 512 MB of a RAM and a 512 MB of an internal flash space, a digital compass and a barometer and of course a GPS and the 3G modem). The whole thing should run smoothly and it is expected to have less hardware bugs.
There are also disadvantages. The biggest one is the price. One can buy a mainboard for 666.66 EUR or a complete phone for 749 EUR. Obviously it is not cheap. The main problem is that the Golden Delicious can not obtain hardware components in large qountities which means that they have to pay much more than large phone makers.
Anyway it is possible to get it for a much lover price – for 474 EUR or 499 EUR. There is something called a “GTA04 Group Tour”: you may order it for the price right now. If there will be enough buyers (350-400) then the GTA04 board will be produced. If not then the money will be refunded. You may find more details here. It is an interesting possibility so I ordered one.