One of the big issues that faced open source has been its general lack of off-the-shelf support; the main reasons being that (1) open source is fragmented with a kaleidoscope of projects ranging from legendary ones - Apache, Linux, MySQL, Open office, to lesser known, obscure ones (2) many of those projects fill a particular gap and if that gap affects only a few number of people, then the project will be popular, but only amongst a few afficionados (3) never underestimate people's inertia. If someone wants to get support for open source software, if s/he is ready to do the leg work, chances that someone has the answer to a particular problem are quite high. But then, we, human beings, are right-here-right-now beasts (4) people behind most open source projects do treat them as sidelines, pet or hobby projects rather than their main bread-winner (5) whether you want it or not, open source is still about getting dirty with code. Projects like Fantastico (opens in new tab) have simplified people's life quite a lot but this is the exception rather than the rule and for a rookie to have a discussion with a geek about Linux Kernel Drivers can be frustrating.
So that lack of support is currently hampering the penetration of open source, especially in the small and medium business segment. Demand is probably outstripping supply which is why larger companies can afford open source consultancy. As disruptive as it may be, I would love to see a big company like IBM launch a one-stop shop to provide tier-one 24/7 support for the largest open source projects out there, not Linux, but everything from PHPNuke to MySQL, Openoffice.org and the likes.
I'm pretty sure that the biggest obstacle facing open source is not about mindset, awareness or price. It is about support at the end of the day. "Where do I start?". Everything from consultancy on how to setup an open source architecture to the legal aspect, format conversion etc has to be tackled and even with all your will, it can be very difficult to get a quick and clean start.
Someone out there, from one of the big consultancy and management company, must have seen this golden oppportunity to make a kill - this is an untapped multi billion market. SugarCRM is an example of a company making good money on an open source solution. Now multiply that by 100 other projects and you will get a viable competitor for giants like Microsoft and Adobe.