The Raspberry Pi Pico is now available with headers, ready to be used in solderless breadboards for rapid prototyping.

The specs are the same as the original Pico which include:

• RP2040 microcontroller chip designed by Raspberry Pi in the United Kingdom
• Dual-core ARM Cortex M0 processor, flexible clock running up to 133 MHz
• 264kB of SRAM, and 2MB of on-board Flash memory
• Castellated module allows soldering direct to carrier boards
• USB 1.1 Host and Device support
• Low-power sleep and dormant modes
• Drag & drop programming using mass storage over USB
• 26 multi-function GPIO pins
• 2×SPI, 2×I2C, 2×UART, 3×12-bit ADC, 16×controllable PWM channels
• Accurate clock and timer on-chip
• Temperature sensor
• Accelerated floating point libraries on-chip
• 8×Programmable IO (PIO) state machines for custom peripheral support
• Datasheet

The debug connector is a JST-SH 3-Pin (which isn't used by most peopel - so don't stress about it!).