Yes the solar system does cross through the galactic plain... but not in 2012, or any time soon. this sort of movement takes thousands of years. In your lifetime it would be nearly impossible to measure any movement visible. I refer to this as progression, but except that, that may not be the term widely used.
As to your question regarding apparent brightness... I would assume atmospheric conditions have changed since you last studied the sky.. Like bush fires in Indonesia, or volcanoes in the Philippines...There are a lot of reasons why your sky might look clearer than last year. Enjoy it. It may not last.
From my vantage point the milky way covers the whole sky... and is often mistaken for a cloud. But this is because I live in New Zealand.