What the others replied were mean to say that you should at least tell us what you usually shoot, and why you are looking for a faster lens or camera. If you shoot most low light stuffs, then perhaps a fast lens is the better choice. You can upgrade to a 6.5fps camera but then it's no use if you shoot landscapes, that's why people are asking.
chjing, hope you can take things positively. even if you go to the outside world, it is going to be the same. if you ask for help, then you should also provide some self-help so that people can help you. moreover, it is not as if anyone owe anyone any advice, anything that is given is a bonus.