I have acctually done this yesterday and everything went smooht.. i did not do any hacks. but i do control my old domain though. so i wanted all users to get to my new domain automatically

by adding this file on my in my old domain everything worked straight away

# BEGIN WordPress

RewriteEngine On

RewriteCond %{HTTP_HOST} !^www\.ellisons\.se* [NC]
RewriteCond %{HTTP_HOST} !^$
RewriteCond %{HTTP_HOST} ^(www\.)?([^.]+)\.
RewriteRule . http://www.ellisons.se/%2%{REQUEST_URI}
RewriteCond %{REQUEST_URI} ^(.*/)index\.html$
RewriteRule (.*/)index\.html*$ $1%1 [L]

# END WordPress

i moved from bengt.fambrodin.se to wwww.ellisons.se/bengt