If you keep moist (from sweat and the ice) boots and blades in an unventilated bag or suitcase, they tend to rot, mildew, or rust. That doubtless depends on the amount you sweat, and the climate - but, because skates and blades are expensive, a major pain to modify to fit, and we want them to last for years, many of us choose to be cautious, and try to let them air dry. So if you have a choice, don't put them in a bag or suitcase. But you might not have a choice when traveling by air, train or bus.
Mesh backpacks and duffel bags are frequently used for sports equipment, so the equipment can air dry. Not perfect - but the mesh helps a lot. For example
http://search.nrs.com/search?w=mesh%20duffelor search for "mesh duffel" at eBay.
Obviously, the more open the mesh, and the less tightly you pack your bag with other stuff, the better the ventilation.
Mesh bags would let the moisture out. Unfortunately, they might also let dirt in, which I suppose might be especially important if you check your bags. There are also suitcases with a ventilated shoe compartment - but those compartments may not be large enough for your skates.
Many people wipe their boots and blades dry with cloth, inside and out, then carry the cloth on the OUTSIDE of their bag. They may use a second oiled cloth on the blades to slow rust. And use soakers, not plastic blade guards. When carrying boots in my car, I leave them out in the open, and leave the blades uncovered, and take them indoors to a low humidity indoors area as soon as I can. If I have a lot of stuff to carry, I sometimes use a mesh grocery store bag. (Cheap!)
If you carry your bag outdoors in the rain, an open mesh might not be an ideal solution - unless you also carry a waterproof bag that can go around it if needed.
Of course, I haven't answered your question. It depends on how much stuff you have to carry, so I won't.
P.S. Some countries don't allow skates with blades in carry-ons. Research it.
Happy skating!