I would say this is the only news podcast you need, but actually I recommend two. BBC Global News and NPR Hourly News. This podcast is from the BBC and has a worldwide news focus. This podcast is about 30 minutes long and comes out twice per day.
The other news podcast I subscribe to is hourly, but short (5 minutes). What I love about the BBC Global News podcast is the 30 minute length is enough time to delve deeply into a few different news items. I really think 30 minutes is perfect, long enough for a few interviews, but short enough to get your news and move on. Especially for those of us that listen to all podcasts at 2x speed!