I seem to be constantly bemused and irritated by some of the things that I find, or find missing, in my dealings with Magento.
Some of these are simple code quirks, such as spelling mistakes in code that are repeated elsewhere by necessity (what does the variable $accress do?), others are amusing comments ("TODO: ask Moshe about this"). Most irritating are the features that one might expect, based upon what is already there, but that don't exist – being able to restrict user access based on store for example.
One thing that I've spent a bit of time working on lately is being able to sort products by their average rating. It seems to me that, if you have a rating system and the rating is displayed on products, then it would make sense that you'd be able to sort by those ratings. Apparently not.
Whilst I do hope that some of these major annoyances will be fixed in the future, a part of me also hopes they don't as it will mean all the work that I've put into them will be rendered meaningless! What would be really nice would be if Varien accepted patches for Magento. That way we wouldn't to expend even more time trying to "extensionise" something that should be in the core system anyway.
Magento as a product continues to progress but sometimes I wish the community had more involvement in direction and helping it move forward.