I have my site hosted with yahoo. I initially registered the domain with them but transferred domain reg to registerfly and still keep yahoo as host.
I'd recommend keeping domain registration seperate from the hosting.
I've had problems with yahoo and their support is usually not good, hence moving the registration away from them. However, I do like their hosting, maybe because I've been with them since I started my site and am reluctant to move. I find their hosting reliable so far.