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.
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.