In a brief post discussing Dell’s upcoming, Android-based Streak mini-tablet, John Gruber of Daring Fireball has suggested the fourth-generation iPod touch will be arriving soon. “If you wait a few weeks to buy the [iPod] touch, you’ll get one with a Retina Display and dual cameras.” Photos of a supposed fourth-generation iPod touch LCD panel with a hole for a FaceTime-capable front-facing camera emerged last week, following…