Does anyone know/guess how many publications for an entry level professorship (assistant professor) is required/recommended? Some people say 10+ conferences and journals, others say its all about journals. Any idea?

I know three people who got an assistant professorship in the last 3-5 years. They all had 10-12 publications at that time (journal papers and journal reviews).
Two were working 5+ years as post docs in the same group, got more and more responsibilities and then got the chance to start their own groups. The other one started at a different university and had the strongest publication record including one nature first authorship. He said that he would've probably not gotten the position without this paper, so I would assume that the journal class is important. It makes also sense as high class journals usually demand much more data and work.

It is of course also a lot of luck. If they are opening a position that fits perfectly to your background then 8-10 publications and a promising research project might be enough...

Don't know if that helps ;)

Conferences v journals - this is discipline specific. Some subjects e.g. computer science seem to put weight on conference proceedings. Others e.g. social sciences, would say conference presentations are nice to have, but do not count compared with journal articles.
How many? Again it's subject specific - lab sciences where multi-authored articles are the norm, are always going to expect more than subjects where single-authored articles are more the norm. It's also going to vary depending on whether you are applying to teaching or research-intensive institutions. A good rule of thumb is to look at the most recently hired academics cvs and see what they would have had at that stage.

I forgot to mention that the three people I was talking about are biologists (plant science). I never heard that conference proceedings are of special importance in biology if it comes to these positions. I am very sure that the journal publications are by far the most important thing. First author is of course more than a mid author publication but it is also impossible to have 10 first authorships. The people above had like 3 first authorships, the rest was second, third and so on...

But that's just for biology and might differ from Europe to Amercia.

Thanks Dunham and Bewildered. I did some research on few faculties related to my field (chemistry) and it seems that having 8 ~ 12 publications has become a norm for first tenure track position. Also because of funding cuts happening these days, my department does not hire candidates as assistant profs directly. They hire you first as an instructor and based on the student ranking on your teaching and how much funding you can attract, then they might promote you to the next level which is assistant prof.