Very Nice Job!
The speed improvement on Mac OSX 10.6 especially when working with one huge html file are truly amazing. No visible delay in loading even huge files and no problems using find and replace to insert chapter break markers and breaking things further.
Very very nice job!
I assume you built a universal app with 64bit support under Mac OSX since I only saw one Sigil.app in the dmg. From your wording in the above post, I almost expected to see 2 different apps in the dmg (one for 64 bit).
I will keep playing around with it over the next few days and let you know how things work out.
Given this new version and your new epub validator, now all we need is a spell checker to make things quite complete (and allow me to get away from OpenOffice completely in my work flow).