Do you think any European league will be happy about having to have a large break in the middle of a season. It won't just screw up one season, but the following one and possibly the prior one too. Still think it will happen though, a summer tournament in Qatar is just not feasible.
3 weeks for a world cup ?? The tournament lasts 4 weeks and the national sides would need at least 2 weeks before the tournament for squad training, so unless they change things drastically, it's at least 6 weeks in the middle of a season. I think it will happen though, somehow.