I don't think any of the AVR USB microcontrollers come in a DIP format. Sockets for the available formats tend to be pricey, large (relatively), and not a good choice for high vibration environments.
Why do you worry about being soldered down? I suppose if you are going to accidentally blow the chip it is a cheaper repair, but with a cheap hot-air unit and the video tutorials at SparkFun you should be able to replace that chip if you like. (You will have to figure out how to load the initial bootloader if it is different from the one supplied by AVR, but AVR's is sufficient.)
If you do blow a pin, it probably isn't a total loss. I was winging a little change to just such a processor and ran a 24v line to a digital pin. The pin stopped working, but the rest of the chip continued just fine. The moral is for prototyping you can just use different pins, learn your lessons, and your final deployed unit should be fine.
And with proper design you won't blow the chip. Let me rephrase: with proper design, the only thing that will blow the chip will blow the entire board!
Proper design doesn't cover: "Oh look, I can also monitor the 24v battery level if I stick a little voltage divider onto this extra pin" followed by soldering the pin to the wrong end of the high resistor 30 seconds later and powering up.
Frequently these breadboard type computers get accidental shorts from large fingers or are attached to incompletely specified devices ripped from old equipment. That's the only pin I've ruined in many projects and lots of breadboard work, but it happens. It's nice to know I can just move to the next extra pin and continue.
[Shrug]
At risk of sounding like a curmudgeon: learn to be careful, this isn't software.
With experience some things become second nature: no loose conductors on the test bench; double check before powering up; test one change at a time; add a temporary BIG resistor to any input that's over the PS voltage, don't change connections with power applied, etc.
Ask me how I know that EPROM based devices release a pretty purple flash right before the smoke comes out :-)
Because it isn't necessary for my robot to carry around a programming board. If I come up with another application that uses a microcontroller, I have to pay for another USB programming board/AVR combo.
Why do you worry about being soldered down? I suppose if you are going to accidentally blow the chip it is a cheaper repair, but with a cheap hot-air unit and the video tutorials at SparkFun you should be able to replace that chip if you like. (You will have to figure out how to load the initial bootloader if it is different from the one supplied by AVR, but AVR's is sufficient.)
If you do blow a pin, it probably isn't a total loss. I was winging a little change to just such a processor and ran a 24v line to a digital pin. The pin stopped working, but the rest of the chip continued just fine. The moral is for prototyping you can just use different pins, learn your lessons, and your final deployed unit should be fine.