No, SWAP is for memory management.
Apps2SD just changes the storage location where all your apps are stored to a partition on the SD card instead of the local system flash memory.
There's been great debate on the benefits / drawbacks of Apps2SD but IMO it boils down to this:
The benefits:
Apps2SD is really useful if you have so many apps you do not have enough space to store them on the phone memory. Using the SD card to store the apps gives you basically unlimited storage space (as many apps as you can fit until your SD card is full)
The drawbacks:
With Apps2SD working, you're tied to your SD card - if it should fail, your apps are gone. If you should want to remove the card for some reason, you have to power-off the phone to do so.
Applications like Nandroid *do not* always backup the SD card partition, and may not backup your apps. Other means may be necessary to backup your applications, and there will often be problems on restoring from a backup that doesn't contain them.
The SD Card bus, while comparable in speed to the on-board memory, does introduce some latency - apps will take ever-so-slightly longer to load from your SD card.
[edit]
flipzmode from XDA has a post in his FreshRom thread that describes some of the issues with Apps2SD as well:
http://forum.xda-developers.com/showpost.php?p=4942088&postcount=2
Personally, I've found that the available space on the phone is plenty for the apps I use, and it's not worth the risk involved to use Apps2SD as I tweak around in my phone *a lot*, and have used Nandroid restore more times than I can count
