Some things to keep in mind about NetApp SAN. It's not true SAN first of all. It's SAN, on top of the waffel (sp?) file system which is awesome for NAS, but isn't go great for SAN, especially with another layer between them.
Because waffel is between the platform and the fibre ports if you blast the WAFL with data the FC can then slow down while it waits for the waffel to catch back up.
You also don't get any control over RAID level (unless this has changed recently). So if you need RAID 5 for some data, because it's all read, and some data needs to be RAID 10 because it's all write and very little read you can't control this.
Now don't get me wrong, NetApp makes an amazing NAS unit. But you can't take a NAS, and slap FC ports in the back of it and called it a SAN.
Now, I know that the units can be made redundant, but I believe that requires the purchase of an additional filer head (dual heads are standard is most all SAN setups in case of reboot, etc) plus the additional storage for that second filer (as I don't think that the two heads can talk to the same disks).
Take a look at this blog from Chuck Hollis and the Prove It Kit he published
I know that there used to be an issue with battery backups on the NetApp SANs. If you fired up SQL Server and created a table and started inserting data into it, then pull the plug on the NetApp (simulate power failure) then query the cache to get the last value inserted you'll get a different number from the database after the NetApp comes back up because some transactions where lost (this is an old issue and is hopefully solved now).
The NetApps don't allow you to control the amount of Read Cache or Write Cache. It's 50/50. If you are going to be hosting databases on that read cache is basically worthless, and write cache is king. Normally you'll want to disable the read cache for the SQL Server's LUNs and up the write cache. Not an option here.