Deleted Google Talk on accident
I was just browsing around for this issue and found this,


    I had exacly the same trouble with Google Play and I have managed to revert it 
    back to original working version of Android Market. In Options (Android system   
    settings) go for Applications. Choose Google Play. Clean cached data. Remove this 
    application. After these steps Google Play dissappeared from my droid and I could   
    put back Android Market icon onto my desktop and I can use it for installing new 
    programs. 



Link to source : Link to forum