Barbie, I worked in Saudi for eight years. Most of that in Riyadh. I absolutely loved it. The last time I was there was in Sept. '05
Taif is a lovely city - much cooler than say Jeddah. True, the Filippino nurses are not treated as well as western nurse, which somehow includes South Africans, but all the Filippinos I spoke with said it was much better conditions than they'd expected and the pay was far more than they'd make at home.
The only thing to keep in mind about the money is that, while it is a lot more than at home, and your rent, utilities, meals, transportation, uniforms etc. are paid for, the groceries you buy will be considered expensive. Same price for everyone. Also any clothes you buy, though some places, like the souqs have tiered prices. Westerners pay most, Filippinos in the middle, and Saudi's the least. Helps if you bargain.
I would say to go. It's only a year contract, which is very unusual for Filippinos, and you'll have an entirely different experience to add to your life. Also, since there are so many Filippinos there, it is a very social time. Unlike now for westerners, since so many have left.
I never felt afraid, and the Saudi people are lovely. The press plays up problems and it may scare you, but it is really lovely there, and you'll get to spend your time waiting for your U.S. visa learning new things. The Saudi hospitals tend to have the latest equipment and techniques and the doctors are happy to explain and teach. Military hospitals are good as well.
Good luck with your decision!