For most of my life, my interests have shifted relatively quickly: I spent a month or two learning thing #1 before then discovering thing #2, putting the first on hold and so on until maybe I discovered some interesting insight that got me back into #1. Learning anything else other than the current interest is a slog, but so far that worked in my favor as being a jack of all trades, master of none was beneficial as an undergraduate.
Working on my final project is making me realize the shortcomings of such approach: I keep procrastinating and sometimes missing deadlines because I get interested in orthogonal topics; I need depth of knowledge rather than breadth; learning as an end in itself makes me uninterested in practical applicability. Despite that, I don't see myself as dysfunctional, but rather just far less productive than I know can be.
I am interested into pursing an academia path, but I can't see myself as I am going through a master's, let alone a PhD. The outlook of going to the industry doesn't seem much better either.
So, cutting the chase short: how can I work on improving this situation? Any advice would be greatly appreciated.
To maintain interest in something your brain needs to you see improving in it / getting better at it over time.
Also you have to convince yourself that there's a worthwhile future at the end of the tunnel, and that it's not a waste of time.
Now, if you're talking about depth over breadth in terms of projects, and you just can't maintain focus on one, I am in the exact same boat.
The only issue I see here is the missing deadlines part. I think you just have to be more disciplined and make your grades a priority.
1) Don't do things by yourself. You're more likely to switch tasks because doing so won't leave anyone else in a lurch. Incorporate others to play parts in whatever you're doing so it's a team effort.
2) Announce your projects and a deadline for them in public, either on a blog or twitter. You wouldn't want to appear as someone who jumps from task to task if people are aware of a previously-announced project and deadline.