Is FSP Hexa 500W enough to power up my current spec and future upgrades?

Current rig:
i5 2300
4x2GB RAM
P67 ATX Mobo
GTX660
3 hard disks
4-5 LED fans


Future upgrade:
Xeon
4x2GB RAM
Z77 mATX Mobo
GTX660
2 hard disks
2 LED fans


Currently using Tagan 700W, but I'm thinking of downgrading it coz I don't think I need that much power.

Saw Xigmatek Tauro 500W selling for quite an attractive price too. Is that a good choice?