The steroid hullabaloo may prove to not much of a serious issue this year... the penalties for getting caught don't really create enough of a disinsentive at this time. But over time, I expect to see power numbers go down to more traditional levels due to stronger and stronger policing and penalties.
Big name players may be affected more, since a part of their value to teams and cities is in their reputation and character, so they may have more of an incentive to clean up right now.
Of course, all this assumes that the use of steroids is "predominate", which, by the way, I still don't believe is the case.
However, lesser known players, those who haven't established themselves, may still think it's worth the risk to bulk up over the winter in the hopes of a career year. So... if you know of a player that has reported to camp having "gained 30 lbs. of muscle", he's surely worth a flyer in your fantasy draft- and he's also a candidate to feel the wrath of the "'rhoid police" sooner than later.
IMHO- ask the batboy.
"Baseball is 90% mental.., the other half is physical".