Well - - Yes- sort of
Since there are, to date, NO viirii in the wild, the appearance of one would be an increase. The increase in numbers of Linux machines is less the issue than what is to be gained by the cracker. No profit, no attack. Given the general profile of Linux users, if a successful attack was crafted, they would detect and kill it quickly. Thus no profit. It is possible there may be a few crackers out there who would go to the time and trouble of writing malware for Linux just to prove it could be done, but I do not forsee any serious efforts.