It's important to keep track of what's going on in your office. Sometimes, you can take this too far (and turn into that nosy person that every office has), but there are ways to keep track of what's going on. Doing so can keep you in front of the winds of change so that you're not blindsided by unexpected events.
There are many standard ways to find out what's going on including departmental meetings, listening to office gossip, and the like.
One thing that I've found that works to give me some extra insight is a simple trick:
Keep an eye on the conference room schedules.
In our office, anyways, the conference rooms are booked through Microsoft Outlook. When you're setting up a meeting, you can reserve the conference rooms simply by ‘inviting' them to the meeting. If nobody else has booked it, the conference room will then be booked for you automatically.
This can be useful because, at least in our case, we can view the calendar of any conference room. I can see who booked conference rooms, what the meeting is for, and who is attending. While this probably won't give you any big information, if you see HR booking interviews, it might be a good sign that the company is doing well (or if HR books a big block of time with a vague description, maybe not). If you see a bunch of vendor meetings or project meetings, you might get a heads up on big things that the company is planning. If you see long term strategic planning meetings, you might know when to drop a casual inquiry to someone in management that could get you assigned something big.
I tend to peruse the conference room bookings every couple of weeks. I've never learned anything that made me gasp in surprise, but I have learned a few interesting things along the way, and you never know what information might come your way.
Have you ever monitored the conference room schedules (or the conference rooms themselves if you have a good vantage point) to get a feel on what's going on in your department?