While weapons in space will come, the US shouldn't put weapons into space, or at least it shouldn't be the first to do so.
If the US does put weapons into space, you would possibly end up with an arms race with China, and given how China (or more to the point, the US) is at present, I very much doubt the US could win it.
However, should the US get this deal, there won't be an arms race with China, Iran is a long way off weapons in space. (Given that it is building weapons that we have had for 50 years), and the Islamic extremest are never going to get close.
Both the US and China have the capability to destroy space based satellites, so it isn't as if putting weapons up there is going to be the all destroying weapon. The cost of a weapon that takes down a satellite is very very low compared to putting a satellite up their.
If all countries have weapons that do this, how long do you thing the US is going to have GPS in the next war? About as long as it takes for the country you are invading to launch 20 missiles
I think the US should be putting its efforts into fixing its economy, rather than putting something pointless into space to make other nations feel threatened and have to expand their arsenal.