Under the current state of the Startup Visa, does the number of founders matter for the Startup Visa? Is the minimum investment still 250k$ if there are two foreign founders?
The Startup Visa hasn't been passed yet, but there are some problems with it you may want to look at.
http://www.businessinsider.com/why-the-startup-visa-is-actually-a-really-bad-idea-2010-3 You can read through the Senate bill here:
http://startupvisa.files.wordpress.com/2010/02/startup-visa-act_-final-final-1.pdf Look at lines 10-15 on page 2 and you will see that it is for each investor, btw, to answer your question.