This looks real good. Here are my suggestions:
Differentiate between character sheet creation/editing and viewing. In the latter mode, reorganize the info so that more is viewable at once. All those empty lines can be put to better use. Compare, for example, iplay4e's sheet: iplay4e.appspot.com
Use sliders to enter damage and healing quantities, and default it to half a surge value. It's much faster than typing, which is the main annoyance (for me) of these kinds of things. It's also a good idea to add a dialogue button that adds a surge value, and so on. While it's nice to have a shiny electronic character sheet, faster and easy access to these mechanics is the real advantage I'm looking for here.
Have dice rollers pop up when you double tap on skills, basic attacks, or powers. Personally, I'd forget about the modifiers, and just roll two of every dice and 9d20, showing the rolls separately. Remember to not have this popup cover up the area that was double tapped, or make it a move-able window, so you can keep the results while figuring out the modifiers.
Have a conditions dialogue box that offers all the standard conditions and notes when they end (until beginning/end of X's turn, save ends, encounter). Allow the player to add some default conditions, so he can note if he's raging or something else.