Firstly, it's commendable that CIG is trying different things to improve the development process.
However, staggered development is not a magical incantation that turns 30,000 man-hours into 60,000 man-hours, which might be the idea you'd get reading through Staggered Development FAQ:
What it actually means, is each person working on a feature has a longer period to do so, but their workload is doubled. That is, you got exactly as much time to complete the same work as before.
It in on itself does nothing to solve CIGs signature move of over committing each cycle. That is, as long as they remain too optimistic with their velocity estimates for each update cycle, underestimate the amount of work needed and over promise, they will continue to underdeliver patches, the patches will be late, there will be x.x.1 and x.x.2 feature patches outside of the regular cycle, etc. If anything, I'd say 6-month cycles make it harder to estimate the work than 3-month cycles.
Now, it is possible that staggering the development helps CIG to optimize the resource usage, which is the only way you can get more results out of the same resources, but I wouldn't jump on the staggered development hype train just yet.