I've bought 90% of my gifts already. Just waiting for 2 more for my girlfriend and I'm pretty much done aside from odd bits for friends and other family members.
Buying gifts for people is easy, just listen to what they mention about getting once or twice and forget about, and the list will soon be full.
The reason i get it done early is firstly: No Christmas shopping rush, if I go out now the shops around are fairly normal, so I can browse properly and get some stuff I know people will like, opposed to rushing around a few days before and grabbing whatever I can.
Secondly: The post towards December is shocking and I don't want to miss out on getting peoples presents due to snow and the mail being extremely slow.
Thirdly: Allows me to spend money on presents over time, instead of one lump sum.
People say I do it way too early, which I can see why they would, but I just find it much easier and convenient to do it end of OCT/beginning of NOV. I don't see what the problem is if you have the cash spare now.