There is a new article up at IOL: Computers / IT about a new type of virus labeled "Ransom-Ware". The virus-writer wants $200 to remove the virus and not harm the computer & data.
I'm guessing that Internet banking isn't quite anonymous enough to make this commonplace-- too easy for the virus writers to be located.
Radicati Predicts More Viruses
In an unrelated article, the Radicati Group estimates that the 900 million viruses expected to be emailed this year will reach 4.2 billion / yr in 2009. The article goes into much more detail and is worth a read if you like scary numbers.
I'm not sure that I agree that the figure will quadruple over the next 4 years. I'm sure they've looked at trend data. I just don't think that it's possible to know what anti-spam and anti-virus measures will be developed and used.
If 90% of ISP's simply blocked the SMTP port 25 and then used a little connection throttling on their own legitimate SMTP servers, spam and virus traffic would drop tremendously. As the volume of spam increases over the next year or two, I think it's highly likely that ISP's will start to take notice. If nothing else, new revisions of their firewalls and mail transfer software will be smarter by default and make an impact. Just my 2 cents.