A new report from analyst firm Piper Jaffray says that despite Apple's "lagged" stock gains this year, now is a good time to own shares, based on the company's future.

"There are several reasons why some are concerned [Apple] will not move higher, including ownership reaching maximum levels among key investors, tough growth comps over the next several quarters, and lack of share appreciation following a significant beat in March," Piper Senior Research Analyst Gene Munster wrote in a note to investors this morning.

"But we believe that the multiple will expand slightly as [Wall Street] gains confidence in sustainable revenue growth of 25 percent or greater," Munster wrote, adding that "new product categories, and new software announced at [Apple's Worldwide Developers Conference on June 6] will each serve as a catalyst in the future."

Piper Jaffray&39's estimated revenue growth. The other presents new products, cloud services, software and peripherals.

The firm expects Apple's overall revenue to grow by 28 percent over each of the next four years, with products like the iPhone and iPad exceeding that at 30 and 40 percent respectively. Munster says the stock maintains its Overweight rating and $554 12-month price target.

Munster reiterated once again that one of the aforementioned new product categories could be TV sets, which could arrive in the next two to four years and include tie-ins to the App Store. This is based on Apple's recent additions of MLB and NBA apps to its Apple TV set-top box, and the fact that flat-panel TV shipments have been on the rise. Such a product could add 3 percent to Apple's revenue in 2012, the report estimates, rising to 5 percent in 2013 and 7 percent in 2014.

As for the Worldwide Developers Conference, which kicks off in less than two weeks, Munster says Apple could "exceed low expectations" based on assumptions of there not being an announcement of a new iPhone at the event. 2010's WWDC was host to the unveiling of the iPhone 4. So far, Apple has promised to unveil only "a preview of the future of iOS and Mac OS X." Munster says features from these new versions end up being impressive, as well as giving a hint of new hardware features on the way. The venue could also be where the company opens the curtains on its cloud music service, which is nearing completion.

Apple's stock was reweighed earlier this month, in an attempt to rebalance the weighting of companies in the Nasdaq 100 index. Apple went from 20.49 percent to 12.33 percent, though the change did not result in a sell-off or a price drop. Other technology companies, including Microsoft, Google, Intel, Cisco Systems, and Oracle, saw increased weightings as part of that shift.

Apple this afternoon is up $4.19, to $336.38 a share.