is this a joke
No. Not at all.
Tweetie 2 is a clean, elegant, highly functional app to tweet and follow twits on twitter.com
Tweetdeck is a corpulent, configurable, powerful TWITTER PLATFORM to wrangle your 10,000 followers and spend all day long sending twits and retweeting and tagging tweets.
It all depends on what you want to do. If you drank the Twitter Kool Aid then tweetdeck will let you spend hours reading and tweeting. If you're not quite sure why 140 characters is so magical, Tweetie 2 will give you a pleasing app on your iPhone to access twitter.
Which one's best? Depends on you.