Actually, as Sitefinity team is the biggest one in Telerik, we have dedicated resources for both tasks. Most of our developers are dedicated on making sure that Sitefinity is bug-free. The better part of the Sitefinity development team are addressing problems that our quality analysts and clients have reported, while several scrums are working on enriching Sitefinity with new features.
As for the question regarding the fixes, here is what the roadmap page you've provided a link to says:
"With the Sitefinity 4 Service Pack 1 we will deliver bug fixes and fixes
to know issues from the official release. We will also fix the known
issue with Load Balancing."
Sitefinity 4 Service Pack 1 - due in the week of February 21
In other words, the service pack will address the bugs we and you have encountered and reported, and it will be out within a month.
Grisha 'Greg' Karanikolov
Sitefinity Solutions Consultant