Dear dusordua, mcgahat and maulah,
Thanks for your valuable inputs. I agree with you that better to concentrate rather than distributing the miles. Also Mileage Upgrade is another factor... Of course, who knows what would happen US-based carriers....
Since I'm in the burning miles phase with UA, I think I will not accrue EK miles there. For NW, I am almost re-qualified to be Plat for Yr 2006, just keep it.

Probably, I will open the account in EK Skywards and enjoy the Highest-Gold status starting sometime in Yr 2006.
If anyone (esp. who are CO OnePass member or DL SkyMiles member) has other inputs. I greatly appreciate.
Thanks again - dusordua, mcgahat and maulah
Gox