I picked this one up yesterday and Popcap indeed has another winner at a great price $2.99
Every single bit of the fun from the PC version is in the IPhone version that I can find. The touch controls are easy to pick up but are a bit touchy at points. Of course, control is a bit more difficult with your finger as opposed to a mouse and keyboard, but not enough to not recommend the game.
I'm proud that PVZ has joined the Popcap Row on my IPhone with Bejeweled, Book Worm, and Peggle.