python said:
tbh, i have had the same premonitions many times watching him this season. he even has some eccentric traits similar to the guys you mentioned. but i will give him the benefit of a doubt for now. xc-sking is both very similar and different from cycling.
one can argue that the combination of snow condition/skill of norwegian waxmen, northug's better skating technique and his super powerful upper body may give an advantage. but i'd be a fool to fixate on that.
on the other hand, i'd bet that some russian men, but not the girls, were doped again.
Northug's weapons as a skier, are so far beyond what other skiers can, that either Northug is the only skier who dopes, and only cares to boost his sprint, or he is in fact a very unique sprinter, especially when it comes at the end of a non-sprint race distance. He's just weird. I don't associate it with doping. On a serious uphill, he is weaker than non-sprinters such as Bauer (whom I suspect more, despite his great around-threshold level skiing efficiency).
The past Oslo Worlds gave me mixed impressions. Marit Bjoergen was less overwhelmingly dominant than earlier in the year, despite her obsessive "peaking" towards Oslo. She seemed cleaner than she may have been planning to be as she prepared for this peak. That she still won a lot, is because she's Bjoergen, peaks, and well, she was too buff to stand up straight at the celebrations showcase. I saw a bunch of pretty top-fit Noprwegian women, and bodybuilder just after a hard max workout.
Finland got me the creeps at times this season. Odd bursts of speed, from relatively unknown skiers, mid-race in distance and sprint, as well as final accelerations.
Estonia, what is new? Good to learn they have actual self-critical press there.