To upgrade or not to upgrade?

taken near Reykjavik, Iceland

As you might have guessed, I like taking photos. Lots of photos. I've only ever had a point-and-shoot camera (Panasonic Lumix TZ-20 is my current camera), and I can't help but wonder if its time to upgrade to a DSLR. (sidenote - both TZ cameras I've owned, including my current one, have had dust get inside the sensor, which I can see in the photos, hence why I'm thinking about a new camera).

I've seen photos taken with DSLRs, and I like the effects. A lot. I'd love to be able to get the shallow depth-of-field and other similar setups...my current camera won't quite do it. But then I look at the photo above, which is one of my favourites I've taken over the last couple of years. And I remember the story behind taking it....I was visiting the geysir area near Reykjavik on a day tour, and just happened to turn around back towards where the tour bus was parked, and saw the sun peeking out through the clouds (first time all day). I snapped a handful of photos of the scene, and 5 minutes later the cloud had come back over again. I'm glad I had my point-and-shoot that day, cause I'm not sure I would have managed to whip out a DSLR as quickly to get the photo....

So, I think I want to get a new camera (finances permitting). The only question - another point-and-shoot, or do I go for a DSLR?

Any thoughts/comments/suggestions welcome.