I find that I can consistently produce not just a drinkable product, but a very good beer in well under the oft quoted 6 week (1-2-3) timetable. Lately, I've even been able to get great results without resorting to all the crazy gadgetry that you see posted all over the DIY forum and plastered across my gallery. I've been brewing 6 gallon batches of all grain, single infusion mashed, batch sparged beer. I've never filtered my beer, I'm not doing anything complex, and I'm convinced that anyone can replicate the process. From my experience, here are the keys:
Keep the recipe simple. Heaps of spices, large amounts of strong flavored malts, hefty hops schedules, and non-traditional ingredients can force you to condition the beer for an extended period. There's nothing wrong with big, complex recipes, but don't expect a quick turnaround when brewing them.