I don’t believe there are any plans for a real time scanner.
There is a possibility of social engineering, spear phising attacks against Linux, but any notion that an AV is going to protect you is a false sense of security.
Do not run or install attachments from the internet, even if they appear to come from someone you know. (If they appear to be from somebody you know, and there is a reason for that person to be sending you an executable file, confirm with that person before installing.)
Similar advice applies to running macro’s in Open Office/Libre Office documents.
Whenever OpenOffice detects macros in a document being opened, by default it displays a warning and will only run the macro if the you specifically agree.
The safest rule is you should never open any OpenOffice file unless you are sure where it has come from and trust the sender. Note that it is very easy to falsify an email address - if you have any doubt, do not open the document until you have proved its identity. If you need to exchange documents regularly, we recommend the use of digital signatures to certify the origin of the document.
http://www.openoffice.org/security/faq.html#macros