Sorry, it took me so long to get back to you on this, sadievan. I had been meaning to respond but I forgot.
What do I use my Ipad for:
AUDIO
I listen to it all all day at work . I am a big fan of podcasts (to which IIsubscribe through iTunes)and I also have some of my music on it.
EREADING
I use my Ipad for reading ebooks. One of the reasons I got it was precisely because I didn't want to have to choose between Kindle, Nook, and KObo or engage in legal/theological debates about removing DRM, etc,. With the iPad, I could buy and read from any store I wanted to, and take advantage of all the deals.
I commute by Metro to work, so I do a lot of my reading there. At work, the iPad becomes my audio player.
I also read a lot of magazine content with the iPad. If I want to read "free" magazine content, there's a app for that (Flipboard). I I want to book mark magazine articles on the Web and read them later, I use the Read it Later app. I also subscribe to Isaac ASimov SF through BN and as a print subscriber to the Atlantic magazine, I can use their Ipad app for free.
Finally if I want to read comics, there's Comixology.
MOVIES AND VIDEO
I use the iPad as a second TV, for watching struff in the bedroom. Through Netflix I can watch of a lot of BBC TV shows, for example. One app Ididn't mention above was TEDTalks, for when I want a little brain food.
GAMES
Before the iPad, I never really played video games. Now I play quite a few. The iPad seems to to be on its way to becoming the gaming platform of choice.
WEB STUFF
Email, web browsing, Facebook, Twitter, etc. I do just aboutall of that on my iPad now. Its just more convenient than doing it on my PC
PRODUCTIVITY
I use the iPad as a mobile extension of my PC. I do work on my PC, transfer the files to my ipad, and take them with me. Calendaring and notetaking is done on the IPad .
So there you have it. Now you have an Iphone and a KIndle, so you can do a lot of that stuff on those two devices. You'll have to decide whether its worth it to spring for another device.