0: The crux is to buy what you need, not what is best/available/good/bad.
1: RAM : I don't understand it completely. These days I would go for 4 GB DDR3 ( 2 DIMMS). I think it doesn't matter beyond that with 3 MB L3 cache
2: Family preference
2.1: If I want to show off, I might buy a laptop (weight and battery life )
2.2: For Parents, I want big screen (at least 14 inch), not too heavy, reasonably priced, integrated web cam and video, easy to maintain/use in India, CD, DVD, etc.
2.3: For siblings, I would take the same, might take a slightly heavier but faster model, preferably long battery life, slots to connect external keyboard,mouse, DVD etc.
2.4: I heard Dell has very good service in India. So, would prefer a dell for india home.
3: Processor:
3.1: I usually go for something about 1-2 quarter's old. Saves the premium of new processor.
3.2: Processor speed doesn't really matter much.
3.3: These days I prefer to take a high FSB speed
4: I have never tried a tablet. Dunno what that is like.
5: Weight:
5.1: Think really what is a good weight for you.
5.2: I once heard that price rises by about 200$ for every pound less of weight.
6: Battery:
6.1: Battery is also very costly. So, think what you really need.
6.2: I just buy the duplicate battery on ebay/Amazon
7: When to buy:
7.1: A few weeks after CES, late January is when I bought both of mine.
7.2: If you want to get up early, stand in thanksgiving queue as well -- i never do that since I heard, you get same stuff, same price in January. I have kind of seen it hold, so I dont mind.