As internet speeds get faster, wont there become a point where encoding sound data would be uneeded and the raw sound data could be sent across without a problem?As far as this goes, I seriously doubt that it's will ever be an option. Bandwidth translates directly into money. While most home users will usually have some kind of rate-limited flatrate (like 16 mibbit/s DSL or 50 mibit/s optical fiber), servers are practically always accounted for traffic (the same is true for many wireless/phone rates).
You usually have "some amount" of prepaid traffic included, and as you exceed this quota it either becomes very expensive all of a sudden, or you are throttled or cut off. No such thing as "unlimited" exists, although this is something often advertized. When you take "unlimited" literally, what usually happens is that you're cut off the net without a warning under some bogus excuse ("it looks like your server is under a DoS attack") or even without an excuse, and your contract is terminated under some pretext.
It's not surprising either -- hosting companies have to live, too. The "unlimited" bargain is based on the assumption that it sounds attractive to new customers and nobody uses more than a few mibits/s at most anyway.
No such thing as "unlimited" is possible from a technical point of view anyway, if you look at what "typical" datacenters look like.
You have somewhere from 10,000 to 50,000 servers with 1 gibit/s network cards going into switches that rate-limit them to 100 mibit/s (unless you pay extra $$$) in one or two large buildings, and a uplink (usually split over half a dozen carriers) with a total bandwidth ranging anywhere from 50 to 200 gibit/s. Let's assume 10,000 servers and 100 gibit/s uplink, that's 10 mibit/s per server. Consequently, there can be no such thing as "unlimited" because if only 10% of the customers took this offer seriously and literally, there would not be enough bandwidth left for anyone else.
Uncompressed audio consumes 10-20 times as much bandwidth as compressed audio (or more, depending on quality settings), so one could say (in a very simplified way) that it costs 10-20 times as much money. Or, from the opposed point of view, you can serve 20 times as many customers ( = 20x revenue) with the same base costs.
About what challenges you'll face with Opus, I can't tell (first time I've heard of it, sounds promising). OpenAL as such is pretty straightforward to work with, both for input and output. So, as long as Opus "kind of works" (in a manner similar to, say, Speex), I'd be very optimistic.