The fed may raise rates. Keep in mind they originally called for the end of QE3 back in 2013 and people freaked out assuming rates would skyrocket. They didn't... rates were actually down in 2014, and are still below their 2013 peak(looking at 10 yr treasury yields).
So its all guessisms. Plus they are starting QE in Europe so who knows how that will affect things.
Effect on investments.
Bonds: This is pretty easy to measure since bond prices move inversely with interest rates in a predictable manner(at least more predictable than stocks). Look at the duration on a bond fund. If rates go up 1% expect the bond's value to drop by about 1X the duration. So if the duration is 5 and rates go up by 1%, the bond fund's value should drop by about 5% all other things being equal(which they never are). Don't use this as an excuse to abandon bonds. 1. we don't know what rates will do. 2. if you own the bond fund for a longer period of time than the duration(so if the duration was 5 you own it more than 5 years) rising interest rates should actually HELP you. When you own bonds you want higher yields. When rates rise it hurts existing bonds, but as a bond fund swaps out maturing bonds for new bonds at higher rates the bond fund pays more in the long run. If you plan on owning bonds for 10 years or more the best thing that could happen for you long term returns is a rate increase. 3. bonds are still safer than stocks so if your asset allocation calls for bonds... keep bonds in the portfolio.
Real estate probably will suffer some given that new mortgages will be more expensive and no one will be refinancing with higher rates.
Stocks: in the short term, probably some volatility. Over the long term probably not much of an effect. My biggest concern in this environment has been how many people in desperate search of yield have went from CDs/bonds to more risky stocks. If CDs suddenly pay something again they will probably move back to CDs.
Now... this is all theory, and in the real world rates will probably raise very very slowly. Bonds are very sensitive to interest rate changes so they will move inversely to how rates increase. Small increase = small drop in bond prices. Real estate will depend on how healthy the housing market is. If people are moving to the area and there is a lot of demand then a small rise in interest rates probably won't have an effect. If people can barely afford to live in a given area as it is and there isn't a huge amount of demand new housing sales might start to suffer with even a small increase in mortgage rates. Stocks as always are the hardest to predict. If earnings remain strong and rates remain low enough that there is still a clear risk premium for owning stocks instead of cash/bonds then you probably won't have to worry too much. If the risk premium starts to disappear and earnings aren't strong(which could also happen if the fed raises rates to fast) then stocks could take a hit.
Lots of information.... the most important thing I said was, "Now... this is all theory, and in the real world rates will probably raise very very slowly."