Generally I agree with Gruber’s philosophy of iPhone app design:

 “Figure out the absolute least you need to do to implement the idea, do just that, and then polish the hell out of the experience.”
…however in my situation I’ve always felt like I needed to “bootstrap” myself into a position where I could apply this focus to my applications by securing at least one “hit”; or by building out a substantial enough portfolio of applications to become self-sustaining* so I can dedicate the time necessary to apply this level of polish to my applications.
Furthermore, I thought it made the most sense to release applications as soon as they were viable, and allow the market to sort out which ones were worthy of continued development; a sort of “survival of the fittest”.
As the App Store (and my experience) grew, this philosophy has been challenged (mostly by myself) and I’m continually revisiting and reviewing my position.  After reading a particularily insightful article I’ve decided to lean more toward Gruber’s point and worry less about turning out new apps.  Instead, I plan to turn my focus to my current catalog and make sure that each application is living up to its design goals.
I’m not ruling out any new development, but where my priority before was 80% new code / 20% updates I’m going to try and flatten this out to at least 50%-50%, if not 40%-60%.  I have enough historical sales data from my existing applications that I believe I can find ways to make them better, address the obvious concerns first and then move on to making them offer more than their contemporaries.
I also have a renewed vigor toward “marketing”, or in more specific terms, “reaching my audience”.  I realized that my previously negative view of marketing (and my desire to ignore or outsource it) is unwarranted and that it’s just another problem that can be hacked, and if I’m unhappy with any of the current approaches that just means that I need to come up with new ones.

* by self-sustaining I mean that app development (or some form of independent development) becomes my primary occupation