It's not replacing any blog - and the labs blog will actually get upgraded!
But if you think about it; where would a "developer using Qt" (not a "developer of Qt" like yourself) go on our sites to find blog posts to their liking? Examples: non-Doc tutorials, Top 5 Embarrassing Qt Coding Epic Fails, compilations of Qt material in Spanish, Qt Creator tips 'n tricks, Qt Creator shortcut of the day, Qt Creator featured plug-ins, Qt WoW Client developer diaries, blog post 1 in a series of 5 about learning QML for those that barely know java-script and absolutely no c++, Does it QtBlend?, clever use of Qt code that only works in Space, Qt Quick talk, other non-Doc helper material etc.? (those are just imagined examples btw, no promises!) The labs blog target "developers of Qt" (well, not quite true, but it's the "Labs" after all) and are limited to only certified Trolls posting. The PHB blog is at the other end of the spectrum where non-hardcore-developers like biz dev, partnering and our ace marketing team blog about Qt. In between the two there is a large void where we currently aren't providing much (examples above). It's not due to lack of content, we just haven't had anywhere to channel it to in an orderly fashion. When that is said, we're likely to re-evaluate our content map once we see how it turns out, except for the labs blog there should be no holy cows in our yard. ;)