It made its recommendations as the Welsh Language Board (WLB) announced Pounds 2.7 million of grants for local education authorities in 2006-7 for promoting Welsh-medium education.
The funding can be used to support athrawon bro (peripatetic and Welsh-medium support teachers), and residential language courses for pupils. But local education authorities put in good-quality bids in excess of pound;5.5m - suggesting there is unfunded demand for more support for Welsh-language education.
The Furlong review says the education system has a key role to play in delivering the Assembly government's ambitious plans to make Wales a bilingual nation.
But, as noted by the WLB in its evidence, there is "no purposeful strategy"
to ensure enough teachers with the right skills.
In their report, Professor John Furlong, of Oxford university, and his team, say a more detailed study should develop a proper teacher workforce plan for both new and existing Welsh-medium teachers.
It should also map out current and future demand. And it should work out the cost of providing bilingual initial teacher-training.
Currently, providers receive 26 per cent more funding for students who study through Welsh - but not all universities pass this cash on to their schools of education. And students training through Welsh in Swansea and Cardiff are not getting bursaries available to those at other designated "Welsh" institutions.
As revealed in last week's TES Cymru (January 13), the Furlong review recommends all trainees undertake an initial immersion course in the Welsh language. But the key problem is finding enough Welsh speakers prepared to train as teachers, it says.
Iwan Guy, acting director of the National Association of Head Teachers Cymru, said the factors affecting demand for Welsh-language teachers needed more consideration. For example, those trained in Bangor have found it harder to move south in recent years because of housing costs.
He added: "There are more options available to Welsh speakers now, and lots have turned their back on teaching."
A WLB spokesperson welcomed the Furlong report, but expressed disappointment that it had not come to clear conclusions.
She said: "The board agrees the Assembly should establish a new review to consider how many teachers are needed for the Welsh-medium sector, and their training needs."