Andre, I agree that CM and KM are misleading terms (and Nik's assessment of Ektron). It seems to me that the terms encompass a vast collection of solutions and aspects which each address specific needs and/or offerings. Many clients ARE after a web page/site management tool, but call it CMS. Others may be after a more complex variant of the CMS theme, but still call it CMS.
It's difficult to answer the question of "Which CMS should I get?" without understanding the specific needs. As has been pointed out repeatedly, requirements must drive the solution or choice of solution. I find that clients are happier if I sit down and discuss their needs with them, rather than get into volleys over term-definition - but the ability to do that depends on what business you're in. I just try to avoid using the terms at all until I have a basic client-specific context to work within. The use of terms (CM/KM) seem to be most important to product vendors to say to prospects "Hey, we do 'that' too!", or "Look how fancy our product is!" - and unfortunately many companies swallow it completely, what reason is offered for them not to? Few organisations want to go through a detailed education to avoid being hood-winked by some vendor (though in hindsight this opinion changes!). As you can guess, I'm all for having a relationship with someone you can trust who can listen to you and act as translator/filter in terms of finding a solution. Unfortunately, this often just appears as an "additional" expense, rather than good thinking - and finding a trustworthy soul can have its own dangers! My personal goal is to make sure I'm part of the 'trusted' ones. (end of rant) Regards, Nathan Wheat Solutions Architect -- http://cms-list.org/ more signal, less noise.
