The open-source strategy followed by Dimdim makes most sense when customers want to manage the software on-premise, and it's not so important when everything's hosted in the cloud. But it's good to see competition nipping at the heals of giant WebEx.
No, it actually makes the most sense for manufacturers that are looking to embed Web conferencing into other solutions. The same is true for Ringside Networks. Arguably, we didn't need another Web conferencing solution (Dimdim) or social-networking platform (Ringside).
What we do need are such platforms that can be expanded and integrated into other solutions. Open-source solutions that remain islands, developed and deployed by one company, are much less interesting than open-source solutions that are developed and deployed by a community. Community provides the opportunity for Dimdim.
In short, Dimdim isn't cool because it's open-source Web conferencing. It's cool because of what open-source Web conferencing allows technology providers to do with Web conferencing that price and proprietary licensing hitherto precluded.