I would pay attention to local politics & to the success/failure of the local schools. Proximity to the city, quality of schools and development opportunities tend to be the three key factors that drive gentrification and a corresponding rise in real estate values. It sounds like you know the town so you probably have as good a perspective as anyone. Also certain locations have been more negatively affected/infiltrated with foreclosures and short sales since the markets crashed so perhaps this is what you are physically seeing in the last year in parts of Malden. Very few markets are insulated from down turns like these (back bay, beacon hill, wellesley, brookline, areas of cambridge, etc). I can tell you that from my perspective we see lots of young professional families considering Malden.
Here is a link to everything on the market (foreclosures and short sales are marked):