There are more rumors this week that Apple is planning a tablet computer – an internet-enabled device with a large touchscreen rather than a separate keyboard. But the excitement appears to be based on who the rumors come from, not the detail behind it.

The basics of the rumors have been floating around for some time: it’s arguably a natural market gap; the latest iPhone operating system’s code refers to new devices; Apple has filed patents (pictured) which appear to cover a tablet; and the firm has reportedly reached deals with Chinese suppliers for relevant components such as screens.

The sudden flurry of interest this week is down to a prediction by Gene Munster, an analyst for Piper Jaffray. He makes a career of advising investors about the likely moves which will affect company performance. In some cases his predictions appear to be based on fairly simple logic rather than insider information, but firms pay close attention to what he says, simply because he has such a strong (and lucrative) reputation on the line when he makes predictions.

Jaffray believes Apple will indeed launch a tablet computer, likely next year, for somewhere between $500 and $700. He also suggests the device will be able to download and run applications from the iTunes App Store.

Other reports from mainstream sources such as the Wall Street Journal and Reuters this week suggest the device may be larger than previously though, with a screen as large as 10 inches in diameter.

If these predictions do come true, the big question is whether consumers will see the device as filling a gap in the market, or if it will fall victim to the dual problem of coming across as both an expensive iPod touch and a low-spec MacBook.