(Since these photos were taken there has been a cociderable amont of work on the route, including a new bridge - update to follow....)
The best that can be said is bits of it are being built, but most, if not all of it is unsuitable for anyone on wheels.
I tried to follow the route on foot back in August. The first section as you take the right fork just before Prince's Bridge looks good.
However, the path soon degrades as you go under the railway bridges.
Once under Prince's bridge you go up over the entrance to the Manchester, Bolton & Bury canal
and down onto a mud path
which narrows and becomes engulfed in bracken.
Then under the Irwell Street Bridge the path is narrow and uneven
and whilst it then improves, the path goes up a set of steps to get round the Mark Addy
where the pavement doubles up as a car park.
Across the road there was building work going on and the way was blocked.
Further up by Trinity Bridge the path is wide and well surfaced,
but ends in steps up to Blackfriars Bridge.
From trying to interpret a presentation on the park web site there are plans for another bridge at this point crossing over onto a path on the east side of the river flying above this section.
Then just north of Victoria Street Bridge, a new pedestrian bridge will cross back over to the west bank
and into the new Greengate development where work is underway.
The result should look something like this...
Finally there will be a crossing over Chapel Street and the long Greengate bridge under the railway will have a wide segregated path.
The River Park City section finishes somewhere before Greengate hits the ring road.
View Irwell River Path Part 3 in a larger map