Next-gen SingStar is a great addition to the fold
Menu's system has been completely reworked, whilst the original was very simple it was by no means ideal. The new version is much more intuitive and forgiving of making mistakes. For instance the original only remembered a single user name against each microphone. The new allows you to maintain multiple and selection and reelection is extremely easy.
I've been playing with my old PS2 Eyetoy attached and its all very amusing to see and hear my butchering songs. Might be advised that drinking appears to make these things more funny then wince worthy.
No disk swapping, although its not a feature that you notice once your mad the translation. I still go back and use the original disks and imagine I will until my favorite songs are available.
Online store is good.. 41 songs to date.. I've downloaded 14 new songs.. Good range of songs old and new. Will be nice to see some more of the songs I've already got on my PS2 versions. Price is reasonable.. Although I wish they'd at least given a discount for those of us that already have purchased the songs. SD tracks are around 80 megs each.
Only gripe I have is the stability and performance of the online store, which seems pretty glitchy at present. Still once the tracks are on the PS3 there is no lag as there is no slow SingStore service to get in the way.
My advice is if you enjoy PS2 SingStar then this is a must buy.