To women in a Sunday school class: yes.
To a whole congregation of men and women: no.
But, then again, I'm not real for the too-casual, like skinny pants dress for pastors or jeans that some preach in. Call me a fuddy duddy but I think a suit is best for leadership to where in the church. Maybe, skinny jeans if you are a youth pastor but that too is not my favorite attire for a YP. Dress modestly. I would say that in certain situations like preaching on the streets of some poor class urban town like Westside Chicago or southside LA, OK, for long hair on guys. But, otherwise, again, I think, though it's not a 'salvation' issue, we still should try and follow the bible the best we can and IF Paul mentions long hair is not best for guys then long hair is not best for guys to wear in a worship service.