(This is a rewrite of my previous post so it gets properly noticed as a
bug. ;) )

When generating HTML tables with ampersands in the text, OrgTbl outputs
raw ampersands (&) instead of escaped ampersands (&), which renders
the file invalid.  This bug does not affect normal HTML generation when
exporting standalone files.  I'm using Org version 7.01h.  I've attached
a sample HTML file with an OrgTbl table in it so you can check for
yourselves.  Thanks!