For video editing, a SSHD (Solid State Hybrid Drive) will be less satisfactory than it would be for other uses due to the demands large video files put on the limited (generally 8GB) flash cache. On the other hand, the large sizes of video files will mean buying a large SSD (Solid State Drive) which will be expensive. If you can spare the coin for a large (~1TB) SSD, go for it as this will give the best performance. You might want to consider a setup like I did in my 15" 2.66GHz mid-2009 MacBook Pro: I have a 1TB 5400 RPM spinning disk and a 240GB OWC 3G Electra SSD in their "Data Doubler" as my boot drive. You could choose the 480GB 3G Electra as your boot and work drive and keep the not-under-active-editing files on a large capacity spinning drive. Do note that this setup means I have no internal CD/DVD player. I bought a cheap external optical drive in its place.
A very good thing about the OWC Electra 3G SSD is that it connects at 3G speeds in either the Data Doubler position or in the primary drive bay. I have read reports of some other SSDs connected at the lower 1.5G speed even when rated for 6G speeds because of some incompatibility with the mid-2009 SATA setup.
links:
SSD: http://eshop.macsales.com/shop/internal_storage/SSD/Mercury_Electra_3G_Solid_Sta te
Data Doubler Package: http://eshop.macsales.com/item/OWC/DDMBSSD480/