NASA - The Future???

I'm a bit confused by yesterdays US budget, which cancelled the Constellation program. In today's financial climate, I fully understand where President Obama is coming from, after his budget speech regarding NASA, and even voiced the same opinion to some of my colleagues recently. For NASA to spread its wings and oversee joint space ventures with the rest of the World is common sense. But there seems to be a big hole that people have either missed, or are simply not yet ready to talk about. The ISS is still up there, doing it's 92 minute orbit, but it still needs supplies. OK, the Shuttle missions are still on track till the end of this year, but then what? We can't expect the Russians to constantly supply the ISS, with they're lack of resources, or funding. The Japanese are close to sending supplies, and Europe can only afford to send an ATV every 18 months or so. NASA, it seems, have been put under pressure to come up with something quick, and cheap to do a job that NASA had already spent over 15 years developing. What if the toilet goes wrong again and needs replacing? What if Canadarm2 malfunctions and needs replacing? What is the strategy then? No heavy lift vehicle will be available, we just heard about that in Obama's speech. I know that nothing bad will come to the guys on the ISS, apart from possible starvation, But has Obama and his new cronies in administration really thought this through. It doesn't seem like it to me. Or am i missing some piece of vital information?