Apple (AAPL 1.27%) has an event today at 1 p.m. EST, which was announced with an invitation saying the company still has "a lot to cover." But let's face it, there is little mystery to today's event. Most people have started calling it the "iPad event."

Apple will be following the same game plan as last year when it held an iPhone event in September an followed up with an iPad themed event in October. Like last year, a new 9.7" iPad will be unveiled. However, this year's "iPad 5" will see major changes to the design of the product versus last year's fall refresh, which mainly upgraded components internals like a faster processor. Let's take a look at what Apple has in store for today. 

The product

The iPad was first announced in January 2010, and quickly established tablet computing as the next major technology trend. In 3 1/2 years since release, there have been about $81 billion in iPad sales. 

The problem for Apple is that iPad market share has been sliding across the past year. That's partially unavoidable, a lot of tablet growth is moving to emerging markets where tablets can be found for less than $50. 

Yet, we're also in a period of major opportunity for Apple. While analytics data from third parties is hit-and-miss, Localytics estimates that 38% of active iPads are the iPad 2, released back in 2011. 

That is extremely important because it shows that we're approaching a tablet refresh cycle. It can't be said enough that PC sales aren't falling off a cliff because consumers don't still have PCs in their homes, it's just that they stopped upgrading as frequently. PC refresh rates have moved from once every three years to past the four year mark. 

Apple's sales opportunity around iPads changes immensely if consumers upgrade faster. With the iPad 2 being so popular and hitting the point where consumers consider upgrading, a new iPad that is significantly redesigned will present a great opportunity to convince consumers to upgrade to the company's newest offerings. 

What to expect today

Leaked casing for the new fifth-generation iPad shows it'll borrow heavily from the iPad mini's design. That means a thinner build and chamfered edges around the tablet. 

Imagine this, but bigger

Of course, internals will also see a major upgrade as well. The process will get a bump to Apple's latest A7, with added optimization for the iPad. 

One area that's an unknown is whether the iPad 5 will get the same fingerprint sensor found on the iPhone 5S. KGI Securities' Ming-Chi Kuo, who is plugged into Apple's supply chain extremely well, say the iPad 5 will "probably" lack a fingerprint sensor. With the fingerprint sensor widely cited as a primary factor behind the 5S' short supply-it's a difficult part to manufacture-that shouldn't come as a huge surprise. 

So, there you have it. While the iPad mini has taken much of the attention surrounding the iPad line-up across the past year, this should be the bigger iPad's most important redesign since the iPad 2. 

Remember to check back into Fool.com tonight for analysis on Apple's event, and what it means for investors in the company.