If I assign a saboteur card to a fig with a team ability that can not be copied does that mean that my opponents wild cards get no team ability?

Thanks mates.

No. It just means you've given your opponent a really awesome team ability, and you will probably regret doing so.

Funny... but true. Right now, the only abilities you cannot copy are --

Other wildcard abilities (important for Brilliant Tactician use)
Power Cosmic (which I wouldn't give to anyone!)
Outsiders
Crime Syndicate

Any basis in the rules or other rulings for this opinion?

It isn't an opinion (at least not the 'giving an awesome team ability' part. you may or may not regret doing so, so that is an opinion I guess). He's getting it from the Marvel errata:

Saboteur may be assigned to characters that have a team ability that normally cannot be copied. Opposing wildcards would then be able to use that team ability.

I wouldn't give Power Cosmic to my opponent, and you cannot copy wildcard team abilities. Now as far as the Outsiders and the CSA go, those are still usable abilities, even for one wildcard. You should really use Saboteur with those abilities that require 2 or more teammates to work, such as MoE/IL, X-Men/Titans, Sinister Syndicate, and so on. Tough to use if they only have one wildcard on their team.

Very Good suggestions for Saboteurs, especially the SinSyn/Bat Enemies since they don't tend to be as highly priced as the others you mentioned.

When I am in a TK-state-of-mind, I consider the 2000AD/Johnny Alpha a good candidate for Saboteur: His TA is only offensive, so pesky defensive Mystics/Kabuki/aF4 are elimintated, and it is not nearly as annoying as Ultimates on offense. Johnny is always tough to KO, and if he is primarily serving as a launching pad, he gets stuck in the back of the field.