Numerous original equipment manufacturers are lining up tablets to rival the widely popular Apple iPad. The latter has gained acclaim as both a consumer and enterprise device, forcing many OEMs to pick their battles wisely.

For many, this means developing devices aimed solely for enterprise use, challenging the iPad to win favor with companies looking to go mobile. It remains to be seen how this strategy will play out, but one expert for Forrester Research isn’t hopeful.

On his blog, Forrester industry analyst Ted Schadler believes all other tablets – which he lumps into one category he’s dubbed anything-but-iPad, or ABi – will struggle to compete with Apple for enterprise mobility.

“How will these ABi tablets fare in the enterprise in 2011? Fair to partly cloudy, I fear,” Schadler wrote.

He cites three factors as evidence the iPad will still be the dominant enterprise tablet at the end of this year.

Ironically, the Forrester expert believes that the plan to sell enterprise tablets directly to companies will backfire. Hewlett-Packard with its Slate, Research In Motion with its BlackBerry PlayBook and Cisco with its Cius all have plans to sell directly to companies.

While it sounds like a good plan, Schadler contends the opposite. In the days of dual use – business and personal – for mobile devices, tablets sold to companies will struggle. While IT departments find the budget and test alternatives, adoption of these tablets will slow down, according to Schadler.

Also, because the iPad has been shown as a stellar device for dual use, it has more staying power. Tablets directed only at companies may suffer in such a specific market, and OEMs may be subsequently forced to abandon them.

Do you think any tablet devices stand a chance of knocking the iPad off of its top spot?  If so, which tablet(s) do you see will give the iPad a run for its money?