[Online-/Web] presence (and thus) development is ever-increasingly being cast in the light of the "Attention economy". There's lots of material out there, check Brian Solis' recent post for instance. Presence = brand = motivation for consumption = reward from your client.
Most of that is true. However, given the new examination of the bankruptcy of the capitalist model (re: credit crisis) and ever-increasing indications of human-caused environmental change (CO2 emission, polar icecaps melting, etc.), I say that mere attention is cheap. In the post-scarcity dream world that the wealthy of us may have thought we were already living in, it may have meant something (the only thing), but meaning is what people are (always?) looking for and what is needed right now. There are plenty of scarce resources out there still, and there's also the uneven distribution issue.
Given the old question on whether it's ignorance or apathy which is killing the world ("I don't know and I don't care"), meaning without drive behind it means nothing. Take into account the fact that newly adding social media functionality, open (source) develop space and services and/or free hosted services etc. no longer add significant competitive advantage. There's too much internet out there: you have to pick and chose your social aggregator of choice. Something new is needed to catapult newly developed solutions (it's my business, after all) into success. Actually meeting and engaging the faceless masses of users and getting real-world traction is proving succesful. And not just engaging by presenting relevant content: the content's all out there by now (and things like the One Laptop Per Child initiative will also make it accessable).
I'm not talking about IT solutions that engage users/people with the value of "Information should be Free" (or other IT-based meaning). Open Source and Proprietary software are converging their business models, and there's enough surplus talent / dedication / geekery (a good thing) out there out there to mashup anything people may want. This is the 80/20 rule at work: the 20% of interested developers ('heavy users') will make plenty good stuff (TM) for the 80% of the non-IT minded 'plain users' who will be consuming computing/software 'like water from the tap' (SAAS, PAAS, etc.).
When I take my clients into account as a developer and business owner (and not as a systems enterprise architect / language developer at Microsoft, for instance), it seems much more rewarding to build solutions that create the engagement through supporting (non-IT) values. Take the environment, locality-based initiatives, volunteer work, niche hobbyism, or the specific business know-how/product of the client: they are what will build the dedication to the cause and the (web) solution both.
When talking about developing something "for the whole nation/world", the story is somewhat different: all the previous trends mean to me is that there are cheap shoulders of giants to stand on (for deploying a communication platform and allowing others to do the same). The trick is to get people as dedicated to the meaning of say, sustainable consumption, as they are as sharing their music and pictures with their friends. There is a rather close-ranged horizon of care (for others). So perhaps the trick is a 'dedication repository', with merging algorithms. If that sounds too geeky or uses slang you haven't run across yet: "Act Locally, Think automatically merge into Globally".
So, what will be next, after the attention economy? The dedication economy.
(If you're a cynic, call each person's individual dedication/values-in-action the 'long tail' sitting behind people's common basic need for stimulation. If you're more upbeat, it could be the pinnacle of the Maslow pyramid.)