Nearest misses: Belarus, Oman, Barbados and Uruguay. Russia is the only country that is currently becoming less developed and may soon become a developing country is current trends continue.
Only UN members have HDI calculated. Taiwan is probably developed, and Vatican City is such an odd country I don't think it fits into the development model.
Funny thing is North Korea's HDI was calculated a few years back, and they are said to be close to developed. I have a feeling it wasn't very true at all.