Should I upgrade to the new iPod Touch 5th Gen?

Yes, it's worth it. There are lots of differences between 4th gen and 5th gen iPod Touch

See this page (last 2 tables): http://en.wikipedia.org/wiki/IPod_touch#Specificat...

The 5th generation iPod touch features a 4-inch Retina display, A5 chip, 5-megapixel iSight camera, 1080p HD video recording, Siri and 40 hour battery life.

It's available in five colors and in two capacities - 32GB and 64GB. Can be pre-ordered from:

Amazon: http://www.amazon.com/gp/feature.html/ref=br_lf_m_...

or BestBuy: http://www.bestbuy.com/shop/ipod%20touch%205th%20g...

If you have a iPod touch 3G, its worth upgrading. If you have the iPod 4G, then no. The Ipod touch 5th generation is basically the iPhone 4S without the phone, and with a 4" display.

If you wouldn't upgrade from an iPhone 4 to an iPhone 4S, then don't go for it. You really don't need it .

If you want all of the new features plus Siri, yes.