in my experience All of our Aikido Practice is "weapons" practice. It does not matter if you have a weapon or not. Your Bokken, Jo, or Katana is just an extension of your arm... They are not separate... They are completely integrated into every Aikido Technique. What I can also say based on my experience is that you can tell right away who practices this way and who does not and those who do... usually have a better understanding of "how" Aikido works.
In my experience, such dichotomies may be a little misleading.
Aikido seems to incorporate some transferable skills with respect to weapon use. However, a weapon seems to be more than just an extension of your arm. The distancing, timing, relative angles the practitioners are likely to achieve, requisite body mechanics and the overall - for lack of a better word -- tempo of the encounter are very different depending on what weapons and defences you're both using.
I fear, if you try to wield a Jo like a Katana, you're just going to get hurt - just as you'd get hurt if you tried to use a Katana without, among other things, understanding that a lighter more mobile footwork was called for than when trying to wield a fist or to throw someone. Different weights, different penetration characteristics, different lever points, (the ability to rapidly alter your lever points in the case of a Jo,) different speeds at which you can change angles; at least in my experience, they all tend to dictate different, partially overlapping, sets of skills to make best use of the things.