Anti Virus software nowadays rather deals with all kind of malware such as spyware and trojan horses. Such tools (both pro and anti) also available for *NIX. The problem is that 1) people misconfigure software 2) install software from dubious sources 3) software is left unpatched.

Problem #1 example: SSH server on iPhone. We can deal with by proofreading our documentation. That is, we proofread our own and each others' information. Our posts on t.m.o, wiki, mailing list, and so on. Already happens btw, but there is no data available how severe this problem is in Maemo community.

Problem #2 example: are many, but cannot think of one. Is harder to deal with because its the user's fault. However because we have signed packages, and because those who upload packages use their real name, the problem is less severe. Because of open source software widely available we don't depend on closed software or warez. More advanced security layers like capability-based security and DRM probably increase quality of this in Maemo 6.

Problem #3 example: Adobe Flash, Gecko. Is less severe when one runs popular open source software although the less popular flies under the radar anyway. A) If this platform is to survive it needs support for the software, and that means bugs in for example Gecko must be patched ASAP by upstream. That means Nokia. In the past they neglected this, but I believe now they will deal with this correct. B) In case of community-based software, like for example OpenSSH, you're entirely dependent on the package maintainer and their upstream provider and this is one of the reasons Nokia provides no warranty on this software. If there is a market for such a third party could provide a software repository for Maemo for a fee, with support contract corporate users (SLA, blah, enterprise). More likely, is that corporations will deal with this in-house/internally. While one is right to describe this as a risk, question is whether commercial support for proprietary applications is better than community support for open source applications. I don't believe either one is better, it just depends very much on involved factors.