I picked up 3 at Microcenter last week: 1 for me, 2 for two friends that are not near a microcenter location. $1.99 promotional, each.
I started playing with MicroPython official port, but switched to the more friendly Adafruit Circuit Python. I started with Thonny IDE but wound up on Mu which directly supports CircuitPython.
Of course, none of this is how I would use this uC ... I just found it remarkably easy to use a short USB-micro cable, attach the Pico, coil the 1foot cable into a small loop, and plug it into my Surface Pro Windows 10 tablet. Great for CircuitPython playing.
Yes, same could be done on ESP32 or ESP8266 or ...
The board quality is excellent. The USB connectivity is good, no issues w/ Win10. The single button is a one-time thing with Micro/CircuitPython... once the firmware is loaded, there is never a need to use the boot button until a Python firmware replacement.. that is, the virtual disk drive appears instantly at power-on.
When the Arduino core is baked, I will see how Adafruit handles the board differences as the Arduino official product will have different board pinouts... well, reduced uC pinouts because of added sensors.
The Arduino Nano RP2040 Connect has only 30 GPIO pins, versus the 40 present on the Raspberry Pi Pico. What we lose in GPIO pins we gain in extra features, and the Arduino Nano RP2040 Connect will come with WiFi, Bluetooth, and a 9-axis IMU sensor and microphone.