Originally posted by Not a Number What are the chances of water or dust damage without WR?
Pretty much 100%. Any non WR lens needs to be throughly dried if immersed. My FA 50 macro had to be partially disassembled so I could blow warm air through it. People just don't make videos where they rinse off their non WR lenses in the sink. That's a point lost on those critical of the video.
That being said, drying off your gear as soon as possible and not having it exposed to weather for long periods of time is a no brainer. Water has a way if finding it's way into everything over time. My Optio 90W had water in it when i found it after being submerged for at least a month, and run over by ATVs a few times. But it worked when dried out. And it's waterproof to 7 feet, not just water resistant.
Buying a WR lens is no reason for getting sloppy taking care of your gear.
A WR lens will be more resistant to water damage than a non-WR lens. Not impervious, but if you take a lot of images around water, they save a lot of grief. We've immersed two lenses already this year in camera accidents around water and boats. IN both occasions, hours of assembly, disassembly and blow drying was needed to save the lenses involved, I've had WR lenses in similar situations, with no ill effects, needing no more than wiping them down with a paper towel stored in my camera bag.