No. At least not until 802.11n is approved by the IEEE so that all the 802.11n hardware works together. There's no guarantee that whatever you buy can be upgraded to the approved standard.
It's faster than 802.11g at close range. It handles reflections somewhat better than 802.11g.
Probably. Draft-N is just yet another wireless "mode". All Draft-N and Pre-N wireless routers have an 802.11g compatibility mode. You don't get any improvement in performance in the 802.11g mode. It just acts like an ordinary 802.11g wireless router. Most Pre-N routers also have an 802.11b compatibility mode, which really slows down traffic in the Pre-N mode.
Draft 2 allowed for optional channel bonding for more speed by hogging
70% of the available bandwidth. Fortunately, it's suppose to be disarmed if there are any incompatible 802.11b/g etc devices in the neighborhood. Draft 2 also raised the offical maximum speed from
100Mbits/sec to over 200Mbits/sec, mostly because most Draft 1 routers would do well over 100Mbits/sec on thruput benchmark test. There a bunch of minor tweaks which I don't wanna dig into.
starting with "What in the standard".
Approval by IEEE by when hell freezes over, or Sept 2008, whichever comes first.