The only options available online are combined broadband and phone packages.
What follows is what has been established this far. It would be helpful if people who've spoken to Zen sales about their situation reply in this thread to update our collective knowledge.
Existing Zen FTTx customers
During the soft-launch phase, AndrewW was able to switch to Unlimited Fibre 2 without moving his phone to Zen. I followed his example and was also able to switch. The price is the old Fibre Active price: £29.50/month plus VAT (£35.40 including VAT).
This switch could only be done by phoning Zen sales on 01706 902000. I don't know if it is still possible to make this switch now that the packages have been publicly launched.
I was within my 12 month minimum contract period, having paid for my FTTC install in January. By changing package I entered into a new 12 month commitment, but was not told about any early-termination fee for my Fibre Active deal (so, applying a long string of case law on onerous contract terms, especially Interfoto, it would be impossible for Zen to hold me to one).
I do not know how Zen will handle those people who took up the later offer of free installation in return for a 24 month minimum contract period. It's possible Zen may impose some sort of fee on these customers for changing package.
Phil Long has indicated (in Zen's own forum) that those on the old FTTx products with a cap of 400GB/month or more (the old Zen Office and Zen Office Plus products) who switch to the new unlimited products are moved from premium prioritisation to standard. As this involves a change of the underlying wholesale product, I would expect this option to involves early-termination fees if within a minimum contract period. Phil has also indicated that there is unlikely to be any difference in observed quality of service.
Those who do not already have Zen broadband
If I understand jez9999's post correctly, Zen have said they will not offer the new broadband deals to new customers without taking a broadband and phone package. This is is accordance with the Zen FTTx web site - if you press the "Show broadband products" link at the bottom of the page, you are offered the old Zen Lite / Zen Active / Zen Pro products at a new, lower, price. Edit: As Andrew has pointed out, the "Show broadband products" link at the bottom of the Zen FTTx and phone packages page shows the Zen ADSL products - this is extremely misleading on an FTTx page despite clearly saying 'up to 16Mbps', which I'd missed. I suggest Zen replace this roll-down section with a link direct to the Zen ADSL product page to avoid others being misled.
Those who are currently Zen ADSL customers
At the moment, nobody in this category has asked Zen sales and reported back. Who will be the first?
ZeN Unlimited Fibre 2
thinkbroadband speed test : speedtest.net : thinkbroadband quality monitor : pingtest.net
Edited by David_W (Sun 29-Sep-13 12:30:54)