Without a serious "weapon" like a Neptune (price ~ $12,000,000 )  you will be always outgunned as miner.
Consider to invest in coins instead of mining. The BTC price will raise again and you will make a nice profit.

18th December - still no reply - BFL just doesn't care - they probably already got rich as hell with the pre-orders.

If the price crashes too far, everyone will turn off their stuff and the diff will go way down for the few of us still mining out of principle. That might actually be nice, if only briefly.

DVC/IXC are truly worthless.  They would be even more worthless if BTC Guild bothered to merge mine them and roughly doubled their difficulty again.

Knowing the load that altcoin daemons put on servers (because they all use extremely old bitcoin forks), I'm pretty convinced that you end up hurting your earnings more than they will add to them just due to the increased rate of stales/time to perform longpolls/work restarts.  Combined they don't even add up to 0.1% additional earnings *at current difficulty*.

Of all the scamcoins/altcoins out there, the only one that is actually something new/useful is Namecoin, even though I'm personally not a major fan of it.  But all the others are mindless clones of Bitcoin that bring nothing worthwhile to the table.  At least Namecoin was designed to do something outside of a cash grab.