It seems that slow Arduino times completely have past. You can find many different flavors including AVR, ARM, PIC based. Even Intel Galileo is on horizon. It seems that there is another player in a market that offers powerful Arduino boards called 86Duino. DM&P produces low power x86 based processors called Vortex. So they released an 86Duino board that can run Linux, Windows OS or other 32-bit OS.
86Duino SoC Vortex86EX runs at 300MHz and carries 128MB DDR3 RAM. It is quipped with most standard PC periphery including PCIE bus, DDR3 controller, ROM controller, xISA, I2C, SPI, and Internal Peripheral controller with DMA, Interrupt, and timer/counter. Other features include Fast Ethernet, FIFO UART, USB 2.0 and SD/SATA. All this comes from single SoC. 86Duino has a form factor of standard Arduino just a PCIE connector pops on side. Of course there are standard Arduino header with 14 digita l/O and six 11 bit analog inputs. Most of them support 32-bit operations. Boars are announced in two formats – Zero and One which is bigger like Arduino Mega. 86Duino is also Arduino IDE compatible. Same programming experience just more power and freedom.