GF3 vs. GF5?

You should look upon the GF5 as an update to make the range more competitive, rather than an upgrade for GF3 owners.

I would expect the GF3 to be available as a cheaper alternative for a while, until they start reducing the price of the GF5.

I have not seen a GF5, but saw one review that said the screen is has a higher resolution screen (920k dot?) and the sensor may be updated as well.

I tend to think that one should try to miss out a generation or two when upgrading, in order to get a significant improvement. Hence, since I have a Panasonic G2, I am thinking I may purchase the GH3, if it has improvements on the sensors in previous models.