No the perk tree is balanced for 81 levels and three standing stones, warrior, mage and thief. They'd need to add three skill trees one for each aspect. It be silly to add a new skill tree for a weapon that work perfectly under archery.
Archery will probably be modified or updated with some more perks.
God I hope they don't give crossbows their own skill tree. Do like one-handed and give a few perks specific to crossbows. Also if crossbows work EXACTLY like bows (i.e. hold left trigger to zoom) then what's the difference? But I guess that's like asking what's the difference between an axe and a mace...they'll probably fire slower but do more damage or something...not to mention crossbows IRL fire straight whereas bows fire in an arc...
It would be weird if they weren't a part of archery. I mean, considering that hammers and longswords fall under the same category, two ranged weapons should also fall into the same category...