Most expensive option would be quad LNB providing four feeds. That would allow four sky boxes in four rooms or more likely two Sky+ boxes. This would allow you to watch upto four sky channels on different TV's. Requires an extra monthly payment though.
or you could go for something like this in the loft...
http://www.blake-uk.com/prod_products_proception_proSTR.aspxThis takes in an aerial and sky feed and routes both to the master TV location. Other souces at the master TV location (eg DVD player, VCR, or the output from the sky box) are routed back up to the loft box where they are amplified and distributed to other rooms. You can watch sky on any TV but they all have to watch the same channel. Most TV distribution amps like this one support a magic eye or similar.
or...
You could do a combination of both. Fit a loft box as above run feeds to all rooms. Then run two extra wires from the quad LNB to the master bedroom or wherever they want the second sky+ box. The second box could be added later.