Question - if I can connect at a speed of about 450 - is that fast enough for DS/Wii Gaming?
Two things you need to consider with a connection:
1. Bandwidth - "how much *stuff* can i send at once".
Measured in bits per second.
The higher this number is, the better it is for downloading data. For games I don't believe it to be as critical. Maybe someone can pull some numbers out of the air about a good bandwidth, because I haven't really cared about it.
And the data sent down the wire don't match directly with data stored on your computer, but you can get a fair idea of the real data being sent.
For example, my current connection has a bitrate of 512kbps, but when I'm downloading my data rate sits at 50-51kB/s (mostly because of parity bits in the data stream).
2. Latency - "how long does *stuff* take to reach its destination and return to me".
Measured in seconds if you suck, but generally milliseconds.
You want this number to be zero, but due to the speed of light being so slow currently you're gonna notice it when you're talking to hosts around the world.
To see this in action, do a traceroute from your computer (you can even do this from your Wii Browser Channel, google it). The traceroute asks for a destination host and will then display the steps taken to reach the destination, and the latency between you and each step.
For example, I want to know the latency between myself and NWR. It only takes me about 40ms to reach a router in Sydney, but the next router (across the Pacific, probably) takes 190ms. So the distance is going to kill you no matter what.