Sudan President Omar Al Bashir's recent (overnight) comments to 'liberate' South Sudan are likely more rhetoric than substance. He is well aware that the international community are looking for an East African 'hero' in a sea of regional instability. The Republic of South Sudan in many ways must be that hero. To that end there is only a remote chance that, even if Bashir wanted to, the Sudanese military would not be able to cross the threshold into Juba. The international community would likely stand (mostly invisible) behind the Republic of South Sudan. Think Libya.
President Bashir's commented: 'Either we end up in Juba or they end up in Khartoum. The old borders cannot take us both'.
The reality is that neither is likely. The South has not the capabilities nor intent. The North has not the capability. Superimpose that the North risks inflaming the situation with the international community and United Nations and a status quo will likely continue in the near future along the oil band.