You know what's funny? I think both $ony and Micro$oft have different strategies. Micro$oft's approach is more formulated. You envision a product. You throw it out there...Wait for the feedback, adjust your product and try again. M$ has used this tactic with every one of its product. Remember Windows 1.0, 3.0? Xbox 1, was it's first attempt. It will continue to fine tune its product until it's one complete package. Much like M$ Office.
I personally don't think $ony has any grand plan (wild guess). Why? Because when you don't a vision for your product/business, you throw everything out to the market and hopefully something will stick. It's a shotgun approach. Basically, they're providing the platform in which they hope someone else will make something out of.
Why 3 Gb ethernet ports? Possible usages/reasons are distributed computing. Linking up multiple PS3 to create on massive power gaming/multimedia experience. Personally, I don't think developer going to bite this one. Because creating a multi-threaded game is hard enough let alone distributed computing. If PS3 going to multimedia hub, does it need 3Gb ethernet ports? Beside one can assume if you have an ethernet port coming into the PS3, you would already have a home network. Small lan party? True, you wouldn't need to carry a network hub/switch to connect multiple consoles together, but remember that (IIRC) you can only have up to 3 ethernet segments before you need a smart/intelligent router.
Realistically, all the features they're adding are really for a niche market. Dual HDMI, 3Gb ethernet ports and multiple memory slots. All of which are nice to have, but they really appeal to niche market. How many going to have dual HDTV? How many going to have a small lan party without a network infrastructure already? How many prefer to manage their pictures on PS3 instead of a PC? (Actually, I think the 6 USB ports are good, because I'm not sure I like changing batteries on the wireless controllers. Once or twice a month is too often).
Anyway, my point? Don't try to expect much of a plan from $ony. Look else where. See what other companies and people are brainstorming how they're going to utilizes these *value added* ports.