Just throwing this thought out there. With so many companies using Webkit now, and the rendering engine's ability to be ported to the Mobile platform no longer in doubt, it might be time for Mozilla to reconsider its development of Gecko. The reasons are too simple and obvious to ignore any more - the advantages are
1. Standards compliance
2. Lower entry threshold for developers
3. Supports plug-ins and is considered more scalable than Gecko
4. Mobile port available
5. Leaner footprint
6. The code was written with maintainability in mind. By the admission of many core Gecko developers, parts of Gecko are extremely fragile due to legacy
Not a clear advantage, but if more developers work on Webkit, more of its bugs will be fixed, and eventually, most Open Source web browsers will use the same underlying technology to render pages. This will improve the web experience for all users, and with the increased exposure, Webkit's engine will be thoroughly tested thereby producing more bug reports, and ... It's a virtuous cycle that will only reap dividends for all involved.
Whether this will actually happen or not is questionable. If anything at all, with Google Chrome (and Android) picking Webkit over Gecko, this has become an issue of pride with Mozilla's developers becoming fiercely defensive of their pet technology. Once egos get involved, no constructive progress can be made towards the solution I am proposing...