Picaxe has released the PICAXE-28X2 Shield Base to allow compatibility with the many different arduino shields that are available in the market.
Yes !! It means that you can use the arduino compatible shields just by stacking it over Picaxe 28X2 shield base(AXE401) in the same way as you did with arduino and program it in Basic.Also the cost is very low.They have made a statement that its a "No profit product".
There are 3 choices available for buying the product.Datasheet can be found here
1.Pre-assembled - £9.99
2.Self assembly kit - £7.99
3.Only PCB - £1.99
Picture of a assembled shield base PCB
Picture of different shields stacked on top of picaxe 28X2 shield base a.k.a AXE401