After several years of developement, finally we have Bmesh into an official stable release (2.63). Bmesh is the new Blender's modeling system. Apparently, we're going to see little differences, but there are a lot of changes, as the core has been rewritten! Until now, Blender had only support for triangles and four-sided polygons. This ain't that way anymore, now we have n-gons fully supported :) This "little" change, allows us to rething our modeling workflows, as now we don't need to clean anymore triangles and automatic cuts generated when we subdivided a face or an edge, for example. New tools using this feature have been also brought to life, like dissolve, which let us convert a group of faces in just an n-gon, and redraw topology on top of that. Some more tools like bevel and bridge are here, and knife tool has been revamped. We're going to see all of this, and also the Mesh Lint addon, that will let us know how many (and most important: where) our mesh has problems like triangles, n-gons or whatever :)
I hope you understood the possibilities of Bmesh and the use of n-gons during the modeling process. BUT! Keep your final models clean! This means, no ngons, no triangles (some hidden ones aren't really bad at all, but keep the hidden, as they are able to mess with the subdivisions when you use the subsurf modifier hehe)... four-sided polygons is the way to go, n-gons are another tool that helps us during the process for achieving that goal :) See you!