Schwab.com has done a pretty good job of managing change on their site. They
announced the pending change on the "positions" page months before they made the
change, complete with a link to see the new page (not a screen shot, but an
actual page with your stocks). Now, months after the change, they still have a
link back to the old page.
The changeover was done in the light of day, not overnight. It was introduced
and explained, and users had plenty of time to get used to it. Personally, I
love the new page and always went right to the new version after it was
introduced.