There are lots of ways to deal with it... I use the same thing Pete (bullet08) said. Just ignore those little roots on the top. When it has roots lower down, just plant it as if those roots on the top weren't there. Ignore them (so let the top be in the air just like you would if those weren't there). The above ground roots will wither and it'll (most likely) make top growth anyway.
<<edit - it's not too uncommon to see this. In fact, if you put a black plastic bag over the top of a living tree through the dormant season, you may see a whole web of roots hanging from the branches when you take the bag off later. I've seen that happen. If you keep a branch in darkness, it'll try to make roots, and will succeed if it has right moisture and is in an acceptable temperature range). >>
Mike