What are the low cost options to enter the 32-bit MCU / microcontroller market when migrating from 8-bit architectures

There are several architectures that compete for the numerous upgraders that have been working with 8/16-bit so far and face performance bottle necks, limits in available memories or simply look to get a better deal when buying a 32-bit micro with 256KB Flash versus buying an 8-bit with the same amount.

For the competing architectures I limited my list to those that offer low end / low cost 32-bit devices, 32 KB Flash and less. The list will never be complete, it is intended to provide some insight to wider spread devices.

ARM based MCUs / microcontrollers:

Luminary with their LM3S families offers the widest portfolio of Cortex M3 based devices. Starting with several 8KB / 2KB SRAM MCUs / microcontrollers down to 28-pin packages Luminary definitely wants to provide solutions for engineers wanting to upgrade.

STM32 MCUs / microcontrollers from ST Microelectronics provide an interesting alternative. They start at memory configurations of 16KB / 4KB SRAM and offer a 36-pins QFN package as their entry level. This might not be the most hobby-friendly package but for sure it is small and cost effective. 

NXP / Philips MCUs / microcontrollers offer today low end devices based on ARM7, the LPC2103 / LPC2102 / LPC2101 series. Starting with 8kB / 2 KB SRAM combination this option targets the high performance low cost sector. While Luminary and ST offer devices running at 36 MHz (ST access line) and 20 MHz (Luminary), NXP offers a low cost option with 72 MHz. In the near future, there will also be Cortex M3 based MCUs / microcontrollers from NXP under the LPC1000 family starting with the LPC1700 subfamily. Recently NXP showed first silicon with Cortex-M0 core. This new and smallest ARM 32-bit core will make the transition from 8-bit to 32-bit even less painful because low power and low price are main targets for the Cortex-M0 implementation. Real devices of the LPC1100 family, available for the market are still a year away (2010) but definitely something to look forward to. The question might come up why having two cores that are as similar as the Cortex-M0 and the Cortex-M3. A little abstract about this discussion.  

UPDATE:
NXP LPC1100 devices are now widely available and mark the new low end of the 32-bit market with entry pricing of 65 cent / 10K for a LPC1111.  

MIPS based MCUs / microcontrollers from Microchip

Microchip designed a new 32-bit family called PIC32 based on the MIPS4K core. This implementation has a couple advantages and disadvantages over the ARM devices. Advantages would be that the M4K core provides more computing power running at the same clock rate from comparable memory and the fact that Microchip provides free or low cost tools that can easily compete with the free or low cost tools for ARM. ARM advantages besides having many vendors and readily available upgrade paths into ARM9 and soon Cortex-R4 for MCUs are the variety of available professional software tools.

MCUs / microcontrollers from Renesas

AVR32 MCUs / microcontrollers from Atmel

 8 good reasons why you should switch from 8/16-bit to a 32-bit MCUs / microcontrollers

1. You will be more future oriented using 32-bit MCU / microcontroller
2. Many times you get a better value from a 32-bit MCU / microcontroller
3. For complex algorithms, the performance advantage will be huge
4. Most companies that offer 8-bit MCU / microcontrollers also offer 32-bit, the engineering efforts are put into 32-bit. Only limited or often hardly any money is spent on 8-bit
5. "Always on" applications will use less power using a 32-bit because it can be clocked much lower to achieve the same performance
6. Latest market introductions from Energy Micro EFM32, TI, STMxxL, LPC1100, AVR32 and more can compete in every aspect of power consumption with low power 8-bit MCUs even using an apple to oranges comparison when they are running at the same clock rate 
7. More complex peripherals such as USB, Ethernet, CAN, I2S and so on are not available in combination on 8-bits
8. 32-bit MCUs / microcontrollers offer a wider variety of memory configurations and work much better with Operating Systems (RTOS)
9. Using latest manufacturing processes such as 180nm, 130nm or even smaller, the percentage of the CPU in size compared to the whole chip is absolutely negligible 

Why not switching:

1. You have an existing design based on 8-bit and upgrading to the next higher device buys you faster time to market
2. All you want to do is switching some portpins as fast as possible, basically replacing logic gates with a micro
3. No matter how small a 32-bit CPU will get, the 8-bit CPU in the same manufacturing process is still smaller and could provide some cost advantage
4. ST Microelectronics just released new devices of the STM8S family with peripherals compatible to the STM32. Portable software between 8- and 32-bit can make 8-bit more appealing again. 
5. Complexity will delay a first project and could make a company miss a window of opportunity.