Hi!
The problem with the absence of roadmap is a loss of users for Arduino.
I started with an Arduino Uno and wanted more power. Since all the Arduino boards were 8-bit based and the Arduino Due was kept secret, I switched for a chipKIT UNO32: 80 Mhz 32-bit MIPS, 128K Flash, 16K SRAM, Arduino™ Uno form factor and 42 available I/Os.
I'm very happy with my new chipKIT UNO32 board, with enough power, memory and ports for quite a period. The IDE designed by Diligent can address both Arduino ATMega and chipKIT PIC32 platforms. Level of compatibility is good and improving.
Support from Microchip is excellent and very responsive.
So, Arduino and ARM, beware: competitors are coming! 