There could well be 3G connectivity in the forthcoming iSlate from Apple. Why do I say that? Here's my logic:
1. Announcing in January with availability to follow a few months later fits with requiring the device to go through FCC approval. Announcing before the submission puts Apple in control of the announcement rather than risk leaks from the FCC.
2. If it didn't have cellular capability then it would be just like a MacBook or iPod Touch and you would expect Apple to announce and ship simultaneously, or at worst case with just a few weeks delay.
3. Adding a 3G modem allows Apple to distribute through the wireless carriers. It could fit with releasing to Verizon on their new LTE network. The iSlate is not an iPhone and hence doesn't violate the AT&T exclusivity agreement in the USA.
4. Distributing through one or more wireless carriers allows Apple to get the price subsidized. Remember, the 32GB iPhone 3GS is a $699 phone, like many other smartphones - when you buy it without a contract.
