I have to agree. What I think is a big deal here is for developers with families. 45 days is 45 days without health insurance and other important benefits. There is COBRA, but that's two months of paying that bill. For most family plans that's 3 - 4k in expense.
That said, it really depends how much they are paying the prospective employee while contracting. If it's enough to make up for that then it might be worth the risk to some people.
What's that you say? Developers with families and (gasp) kids? You mean developers older than 22, with actual lives and responsibilities outside of work? Inconceivable!
I will say this, though— I give them credit for being open about what they really want. A lot of companies don't do that.
The transparency make them one of the better companies out there. Though I'm surprised this trial period isn't mentioned in their job listings in some way.
That said, it really depends how much they are paying the prospective employee while contracting. If it's enough to make up for that then it might be worth the risk to some people.