Dvorak typist here.
How is Beeminder going to help you with learning Dvorak?
Just switch to Dvorak and start typing. Why would you even need Beeminder??!?
It's not like oh, I am going to type 30 minutes of Dvorak today, then switch back to qwerty again and completely mess up my muscle memory.
Also, the greatest challenge of switching to Dvorak is not the relearning to touch typing on a different layout, but the incompatibility with the workplace. So unless your workplace allows you to change keyboard layout or let's you bring your own keyboard. You should consider these factor because you embark on Dvorak journey.
Mechanical keyboard I would suggest you consider getting are Pok3r or Code WASD because they have a DIP switches that lets you switch to Dvorak/Colemark without the need mess around with the operating system.
Programmable mechanical keyboard such as the Ergodox is also an option, but they are more expensive and esoteric, you can build one yourself or buy a prebuild one on ebay, requires some programming, you can write a code to have any layout you want.
Lastly, it take about a month or two to get back to your qwerty typing speed, so I would suggest you start immediately to take advantage of the holiday break and practice as much as you can by racing on typeracer or something.
Once you switch to Dvorak, no one will be to use your computer/laptop. The look on their face when they use your computer and all they see is random letters when they type lol.