As promised, Lightroom 1.4.1 has been released. Tom Hogarty has posted all the details at Lightoom Journal, including a list of fixed issues. For example
Also import degradation in 1.4 was corrected.
I’ve been using it and have no issues. The EXIF problem is gone and DNG conversions are fine again. I can’t really vouch for the Olympus files, but the one I did get for checking is fine.