I was quoted a couple of times in the recent issue of PMI's PM Network magazine, talking about portfolio management. You can find the article on p. 46 here.
I like to use Stephen Covey's analogy when I talk about portfolio management. Having good project management in place is like climbing the ladder effectively. Having a good portfolio management process is making sure the ladder is leaning against the right wall.
I still see organizations that struggle with balancing the portfolio. Selecting the right projects to execute can be challenging. This involves having some good selection criteria, which should tie to the organization's strategy.
I had a client that changed selection criteria in the past year. The change in the economy caused them to change organizational strategy and they re-evaluated the projects that were important to them. On the flip side, I've seen organizations that aren't sure which projects should be implemented. Sometimes it comes down to the sponsor that makes the most noise gets their way. With resources tight, this isn't the way to manage a portfolio.