Well, it depends. Here's my take...
- Putting the Apps on your SSD will increase the speed at which they run.
- Putting the Apps on your SSD will decrease the available space on your SSD and as SSDs are currently still very expensive per GB, this might therefore be a reason not to do this.
- Trillian doesn't need a fast running hard drive to work well, so doesn't benefit from being on the SSD, plus the AV and spyware can be set to run "out of hours" from your storage drive.
I think the bottom line here is that if you have enough space, then it won't do any harm to load up the SSD with your Apps. If you don't have that much space, then I suggest only putting Apps on the SSD that will benefit from being there due to their need for fast access speeds, such as games or multimedia editors.