Remember the old philosophical puzzler: If a tree falls down in a forest and nobody is there to hear it, are we sure it made a sound? With Tuesday's launch of Office Communications Server 2007, Microsoft is trying to render centuries of existential debate moot. Because as years of hype around OCS show, when Microsoft launches a new product, everyone wants to hear about it.

Today's ceremony in San Francisco, which will be keynoted by soon-to-retire chief software architect Bill Gates, will feature dozens of announcements by telecom vendor partners, as well as testimonies from 155 companies that have beta-tested OCS.

True to its Type-A nature, Microsoft has been preparing five years for today's launch, according to Mike Gotta, an analyst at the Burton Group, who wrote in his blog that it's "one of the most faultlessly executed multiyear strategies that I have seen from a vendor in some time."

OCS, the successor to Live Communications Server (LCS) 2005, adds key features such as Internet telephony and Web conferencing. Some say that on technical merits alone, those changes don't justify the attention OCS is getting.

OCS is a mere "refresh and rebrand" of LCS, said Nora Freedman, an analyst at IDC.

"The importance of this news is mainly that it's Microsoft," said Zeus Kerravala, an analyst at Yankee Group Research in Boston.

Microsoft being Microsoft, many are pinning their hopes on OCS to kick-start the unified communications (UC) market into gear -- something even formidable names such as Cisco Systems, Nortel Networks and others have yet failed to do.

That will help "all boats rise (even those that are delivering competitive alternatives)," Gotta said.

Yet, various concerns -- some legitimate, some pure FUD from Microsoft's co-opetition -- remain. Here are some six examples.

1) Should I entrust my telephone system to a software vendor?

With LCS, Microsoft relied on Siemens Communications Inc. to provide the voice telephony component of the software. But with OCS, Microsoft is doing VOIP itself, an area in which competitors charge it has little history or credibility.

"Microsoft has significantly underestimated the amount of work it takes to build a new voice system," said Mark Straton, senior vice president of global marketing at Siemens, which has since realigned itself with IBM's competing Sametime software. Microsoft is being "somewhat naive."

Microsoft is also minimizing the likely degradation in audio quality as users are switched from conventional PBXes to VOIP-based ones, said Paul Lopez, general manager of marketing at NEC Unified Solutions.

"When you go from a 64Kbit/sec. circuit to a highly compressed 5Kbit/sec. stream, it's like going from a CD to an MP3," Lopez said. "Users may be getting desensitized to what true toll-quality voice should be, but audio engineers will tell you there is a big difference."

Microsoft maintains, however, that OCS' adaptive codec, combined with tools such as the Quality of Experience Monitoring (QOEM) server, which lets system administrators monitor and fix sound quality, will provide as good or better-sounding calls than conventional PBXes.

One OCS beta tester, Lionbridge Technologies, agrees. A full-time user of LCS since 2006, the software localization firm upgraded to OCS nine months ago.

Today, its 4,300 employees -- scattered in 50 offices worldwide -- make 400,000 VOIP minutes worth of calls per month, according to Oyvind Kaldestad, IT director.