Short Term
1. "Server Merger" is the worst phrase a MMO company can use. This will be avoided at all costs, until it is too late.
2. Unless they are free, not enough people will use them to make a difference.
3. Can you imagine the QQ if this happened? Offering a select group incentives is bad press. Just look at the free month fiasco BW just went through.
Long Term
1. This is probably one of the best options.
2. Cooler gear would probably help, but they only have so much to work with. A Jedi in anything but a bathrobe will make people say it isn't SW enough.
3. Actually looking at real playing trends requires paying people who do nothing but that. Just running a script and saying "Oh, this server has 1,000 Republic character and 1,000 Imperial characters. It is balanced" isn't enough.
Sure there are things BW can do to help, but it isn't as easy or cheap as people think.